Not Updated For Current Season
This build is a a fun build, but I will warn you that you are fragile at first, but by endgame you do great damage, your super fast and can basically outrun or catch up to anyone and really be a good ganker/annoying pressure guy, and you have almost 100% crit chance. I have played with the critplank build where you by sheen/infinity edge/blackcleaver/bloodthrist and while this is a very awesome build and you do a lot of damage (If you crit). My build I find out to be super damage and very hard to die because of your speed and you have 40% dodge for melee and if you finish Frozen mallet and 6th item can be randuins odem or ghostblade you can have upwards of 3k hp.
For Runes I choose all Furor for mark/seal, Glyph I choose CD reduction for getting ultimate off quicker. Quin I choose armor pen
Skills I choose to rotate between parley and cleanse/heal and get ultimate whenever avaiable. I find these to be the only truly useful skills. Your E skill is nice for the innate speed boosts, but actually taking the time to shoot minions in battle is often forgotten and so the team boost really isn't that beneficial. I choose exhaust and ghost for my summerner abilities. I sometimes will drop exhaust and choose ignite, but for the most part exhaust is a better skill.
1. Early Game - I try to get mid if I can to get ultimate farm/money and get ultimate early for early game kills. Either if I get solo or side lane I try to last hit with parley as much as possible. I start the game with either faerie charm or regen with hope to build philosopher stone quickly. I choose philosophers stone cause it has good hp and mana regen for annoying laners and it gains 5 gold/5 secs so it regains all the money I spend on it. I have full intention of selling it as soon as I need a spot. Once I get level 6 I fire my ultimate as much as I can trying to get assist/kills and with all the harassment i've done with philo stone I'm usually able to pick up a lane kill or 2 by getting them weak with parley, then popping ghost and finish them.
2. Next I build 2 avarice blades for the crit chance and of course the 5 gold, so with philo stone you got 3 money items going and your getting rich without kills, but of course continue to get as many kills on minions as you can. After I get all this, I build boots of swiftness for speed 3 so it makes getting ganks eaasier. I sometimes buy boots 1 in between avacice blades if I feel like I'm getting harassed and need the speed to stay away.
After I get Boots of Swiftness, 2 avarice blades, and philo stone I begin building infinity edge with getting cloak for crit chance first. Usually when I have enough money for BF sword I sell philo stone for that spot and get it, then complete Infinity edge. Next I just begin building phantom dances x 2, when you finish this usually your close to 18 and have finished all your skills so you are innately speed boosted, have boots 3, and then end up with 30% speed boost plus all the crit chance so you can easily harass and run away.
After that its up to you what you build, I usually like to go for frozen mallet for the hp more then anything and some slow. But you could do Randiuns odem here for defense and the CD reduction which is nice for getting ultimate faster. I almsot never finish a 6th item, but if game went long enough I imagine I would go for HP item just cause I find that to be gangplank ultimate problem is his innate fragility.
Its probably not the most effective build out there, but with the speed its super fun and I usually end up with a decent score just by using ultimate at well timed spots, using parley to harass and then using ghost/exhaust to finish people and chase them down.