Tryndamere's ult, UNDYING RAGE, has been reduced from 6 seconds to 5 seconds, but his base crit chance has been raised from 0% to 10%. this, along with your mastries and runes, can give you a 30% chance at lvl 1 if you buy the BRAWLERS GLOVES.
GLHF
Tryndamere
MASTERIES
normally, i would get the mastery GREED, but i changed it to UTILITY MASTERY (neutral buff duration +15%)
Why, you ask? well, in 30 mins of game time, you will get a grand total of 180 gold from greed, and if you play trynd correctly, then you are getting lots of buffs. So I really don't see why I'd waste a mastery point on the average amount of 6-8 minion kills, or get +15% extra buff duration. it's that simple

This is a Tryndamere build, and my first build, so don't berate me too badly. Tryndamere is a Physical DPSer, and Tryndamere, being Tryndamere, is best at late game, when nothing can stop him. I built his item build to do two things
1: Kill squishy casters in the back of the group
2: crit over 1000 EVERY SINGLE TIME YOU ATTACK (2 times per second)
you rely mostly on your crit chance, and with 2 phantoms and a infinity edge, is at 100% at ALL TIMES, WITHOUT your passive, and attack speed, movement speed, and damage. This will create an awesome Tryndamere that can outrun almost anybody, crit 900s-1000s every time, and reduce a tower to a pile of rubble in seconds.

Bloodlust (Passive) Whenever Tryndamere kills or critically strikes a unit, then he gains 3 attack damage and 1.5-4.5 critical damage for 15 seconds (stackable up to 8 times). Killing or critically striking a unit while not bloodlusted applies 2 stacks instead of 1
(Active)Tryndamere consumes his bloodlust stacks, restoring 10-50 health per stack.
This move is a great move, because it costs nothing, and you get stacks for critting, which gives you more chance to crit, which gives you more stacks. SPAMable because you dont have mana, it gives you around 400 hit points for 8 stacks at lvl5 bloodlust. This is useful with AP, but I personally don't get any AP

Mocking Shout : Decrease surrounding physical champions by 20-100, and slow them if their turned away from Tryndamere by 30-60%.
This is an awesome move, no questions asked. It is spammable, but not as much as 'Q' because early game it costs 40 health which is some back then. Perfect for chasing, it will slow everybody except master yi to a crawl. Plus, its your sonar for invisible units. Twitch creeping up on you? then this will be selectable, and you know your about to be ganked. It works well in teamfights, if theirs a teemo getting attack speed items, then just use this, and now he only hits ones at best.

Spinning Slash :(Active) Tryndamere slices toward his target, dealing damage to any enemies in his path.
(Passive) Slash's cooldown is reduced by 2 seconds whenever Tryndamere critically strikes.
Wait, did you just say it refreshes whenever you crit strike? Yes, and since you attack 2 times a second, then you get it back in 3 seconds or something like that. It's also your free Flash, because you can spin through walls, forests, even barriers like aniva's ice wall or trundle's giant phallic rock. It deals mega damage to minions, and since they stand in a straight line, then its easy to kill them off. be sure to position yourself for maximum damage output. Also, remember that its cooldown is decreased by 2 every time you crit, which is every time you hit. so it comes up very quickly.

Undying Rage : Tryndamere is so mad that he refuses to go below 1 health for 5 seconds, and his abilities have no cost during that time. He also gains 4-8 bloodlust stacks.
This is what makes Tryndamere a man. Since it's cooldown is only around a minute, then its an extremely awesome ult. You don't die for 5 seconds. Pop this ace up your...um.....muscle when you get ganked, or if its a 3-4v1 situation, in your favor. and by that I mean that you are alone, against 3-4 people. Tryndamere likes that. Then Tryndamere crits in their face with his giant sword. but if they stun you at a turret, or something similar, pop it around 20% hp and let the good times roll, because you are unstoppable. Now, it has come to my attention that SO many trynds pop this move WAY to early. POP IT WHEN YOU ARE AT 20% OF HEALTH OR LOWER. Now if there is a AP nuker, like Annie, then by all means be prepared to pop it earlier. But the 20% rule is a GUIDLINE, not a set-in-stone-always-do-it-now kind of thing. <== way too many hyphens -_-

Battle Fury: Tryndamere's critical strike chance increases as he becomes more wounded.
This means that, at 1 hp, you have a 50% critical Strike chance. Use this to your advantage.

Okay, start off with your Brawler's Glovesand 2 Health Potion. now instead of buying an aviarce blade, get a Zeal. Now buy your bezerkers greaves, so you can outrun the enemies if things get hairy. Your movement speed should be around 442. Now finish off the zeal into a Phantom Dancer, and start working on another one by buying the dagger, then zeal, then the whole thing. IF you need some extra firepower, then buy a pickaxe/B.F.S., which will just go to your infinity edge. Then keep building your 2nd Phantom. Afterwords, you should buy the Infinity Edge by buying the B.F.S., then the cape and finally the pickaxe. Congrats! You have the core build in your hands!
Now, for the last 2 spots, here are some reccomended items I would use, and Have used before.
Bloodthirster: lifesteal and damage. kinda obvious.
Hextech Gunblade: it gives you damage, AP, spell AND lifesteal, and it has an active that will slow the target. Plus, you can now spin slash thru minions and get your health back.
Zeke's Harbinger: good team support, plus lifesteal, and armor pen.
Last Whisper: attack damage and armor pen. good for a armored shen.
Youmuu's Ghostblade: cooldown reduction and a good active, its a good all-around item. I would get this late game.
Infinity Edge(again) yep, another one. IF its a long game and your fed, then this shouldn't be a problem. With 2 infinities, 2 phantom's, bez. greaves and a bloodthirster You can easily SOLO THE BARON! and still have 1/3-2/3 of your health!

EARLY GAME
early game, Tryndamere isn't as good as manly, rugged kick-*** Late-Game trynd. He doesn't have the uumph required yet to PWN enemies. YET. Stay in the back, and try to get the exp only. If any minions do go close towards you, then time your hits to last-hit ite little thing, and now you have 2-4 Bloodlust stacks, for emergencies. When harassing, whenever they turn around, pop your 'W' on them, this is a really annoying move, and could potentially make someone have to blue pill back earlier then they want to. That is your harass. Plus if your allay has a range move, then they get more time to use it. Run up to an enemy, last hit, then spin slash away...try not to use health pots a lot, because it may help you to have lower health, it's more of a buffer if a lucky hit really gets you Once you reach level 5, it shouldn't be much of a problem. Also, at that level, start killing the golems that are near your lane, just for the bonus exp and gold.

MID GAME
Mid game occurs around lvl 9-10 with Tryndamere, and by that point you should have a phantom dancer, a zeal, and a bezerkers greaves. If your further, then great!
Tryndamere should now start jungling a little. He can take anything below baron or dragon easily, and can do dragon, albeit with losing some major health. Stay near your lane though, and only jungle if your lane is pushed. Gank the middle by spinning slash into the mid, then when they run, use Mocking Shout. Easy as pie. You have 460 movement speed so USE IT! Ghost is your friend, so use it to get out of there! A useful tip for those who have awesome reflexes is when chasing, pop your Mocking Shout right before Spinning Slash in front of them, which doubly screws them over :)

LATE GAME.
By now, you are a man. You can crit anything, and reduce anything into a smudge in the grass in seconds. If they are stacking armor, then its okay, thats what Last Whisper is for. Most of the time, they run. and thats okay, then mock them in a shouting fashion.
Stay with a squishy person and you take it all, because you can. Need health? Spin into a wolf, golem, or wraith camp and get 8 stacks, for 400 health. Try to get baron at level 12-14. It is definatly possible, and your bloodlust stacks will help if you get ganked. If you DO get ganked, then you can do two things: kill two of them then spin slash thru something they will have to walk around, of spin slash thru the back of the bowl-shaped crater where the baron resides. Then be glad you have 500 movement speed, which has gotten me out of many a 5-team gank.

I like Ghost and Ignite, as they are perfect for what you need
GHOST: an awesome chasing/escaping tool, good early on if you get ganked.

IGNITE: Just what Tryndamere needs early game, if you can't finish them off, cast this, and all their health pot effects are reduced by 50% for 5 secs, and they take damage!

Also good are:
Exhaust: slows them down and they lose attack speed. very class.

Teleport: if ghost isn't your thing, teleport works too.

Flash: Okay, I've been using this move more and more, and I'm considering putting that as my primary. This move is SO FRICKIN OP! nerdgasm aside, who doesnt want 2 spin slashes in a row to catch up, get away, and vise versa.

What not to use. Ever.
Clarity: you don't have mana, you don't need mana.

Revive: HAHAHAHAHAHAAHHAHAHAHAHAHAHA! no. it's good for new players to get back into the fight, and guys that boost the other team.

Heal: if you need health, then kill a minion wave in 2.1 seconds, don't waste a summoner slot, and if you like 5k health but no cooldowns, then go use mordekaiser, not Trynd.

Stay away from people with Thornmail, as it completely obliberates you.
IF your on low health, then use mocking shout to reduce damage coming towards you
DONT rage and quit early on because you die a lot, because you are awesome later game.
This build works for me, but the core build is TWO PHANTOM DANCERS, BEZERKER'S GREAVES, AND INFINITY EDGE. you can change other stuff but that you should keep.
DON'T BUY AVIARCE BLADES as a starting item! I cannot stress this enough. It takes 12 and a half minutes for the gold to start making a profit, and is only giving you a 18% crit chance bonus, instead of 30% from one Phantom Dancer, so build your brawlers gloves into zeal, then get another dagger, then finish the whole thing.
MOCKING SHOUT is your friend! it will slow even a Sivir that casted her ult to a snails pace at level one, and the 500 movement speed you get will make you fly, even as fast as an ult'd master yi!
The total cost of the core build is around 11000, but you easily get 10+ kills to balance it. The other two item slots are up to you, I gave you some ideas in the item section. They are all useful items late game though. With this build, I got an 18/4/9 and a 19/3/10 kill death assist ratio. Maybe i was lucky, but I probably wasn't. This build definatly works on normal PvP games, but I am not sure yet on ELO games

GOOD LUCK HAVE FUN!

Comment if I made any mistakes or if you have an idea that i should/could use. That being said, i'm not going to change the entire build, but i can certainly fit in more strategies.
Comments Help! I do look at them!
-SoulReaper