Pros:
Amazing late game
Skill that can through walls
Great heal
Nice ad debuff
Ddecent slow

Cons:
weaker early game
weak to cc
VERY weak to exhaust
difficult to time ult (e.g. don't ult if you know your going to die either way)

I generally take ghost and cleanse. These to spells allow you to farm safely and escape and chase well.

Ignite: Gives you early game dominance in top lane but becomes fairly useless later on.
Exhaust: Useful for shutting down ad carries, getting kills and escaping. Tryndamere already has a slow and doesn't need this but it is still a viable option.

Flash: Great escape and killing mechanism.

All other spells are bad options for Tryndamere.

It is best to take full crit runes. This will give tryndamere an extremely potent early game. Armor pen runes work as well but are not as effective. Tryndamere needs the early crits a lot.

All other runes are off limits for tryndamere.

Variants

Quicksilver Sash: Do not take this if you have cleanse. Great way to escape cc. DO NOT use this before you ult in a team fight.

Trinity Force: Only buy this if you are well farmed or fed. Great damage, movement speed, crit rate and a slow.

Put one point in spinning slash 1st to escape or win lvl 1 fights. Max q for the heal. Your plus vampiric scepter will give you HUGE sustainability.

Max mocking shout for the slow and then spinning slash at the end.

Jarvan: Difficult to face top especially if he builds armor or begins with armor runes. Just play safe and last hit. He cannot stop you from last hitting too much.

Cho Gath: Play extremely aggressively against him and ensure he doesn't kill any minions to regain his health and mana. After lvl 6 play safe and farm.

Nasus: A key to beating nasus is to watch siphoning strike. As soon as you see one of your minions drop to low hp, walk beside and attack nasus as he siphoning strikes the minion. Don't bother doing this after lvl 6.

Renekton: Many renektons will feel strong enough to take you on before lvl 6. They are wrong. You can easily destroy renekton until 6. After 6 you can beat him as well, however, it is not worth trying as he can easily escape or kite during your ult.

Olaf: Farm and stay clear of his reckless swing.

Rumble: Play aggressive as you can out dps him 1v1. Make sure he doesn't use flame splitter while you turn your back and use your ult AFTER he uses his.

Nidalee: Very hard to kill but, nevertheless, play extremely aggresivly.

Garen: Strongest dps champion early game. No point harassing him due to his passive. Just farm and ask for ganks.

Xin Zhao: Play moderately. Before lvl 6, harass him but ensure you don't go to for to risk your own life. Its ok if he deals more damage back as bloodlust heals more than tireless warrior. After lvl 6 play very aggressively but make sure you do not ult early.

Leblanc: Make her waste her mana attacking you and heal it back. Make sure you don't give he the opportunity to kill you.

Overall: LOOK AT THE SUMMONER SPELLS. IF RENEKTON TAKES IGNITE AND YOU TAKE FLASH AND GHOST DO NOT BOTH TRYING TO 1V1 HIM AND PLAY PASSIVELY. Your 1st priority as tryndamere is to farm. Your second priority is to win the lane.

Casters: Generally easy. Play aggressively and farm.