This guide is still in progress but will be aimed at being a current top lane bruiser guide for GP (dat pirate). GP is an all around decent character in that he has many options for roles or builds that he can play. His gun can be used to harass while auto attacking for last hits if you have a passive lane and want to make the person you are against to have to use their pots and back, also if they choose to stay then you can have them low enough to allow for an easy gank. His gun also has the option of being used for farming the lane if you are against an aggressive top known for being good at harassing, you get extra gold for creep kills with it and it allows you to easily farm from a safe range. His ult gives him a global presence unlike many other farm based top lane champions, you might be behind by 10 cs then oh look a gank is about to happen bot, use your ult behind them and they run through it while trying to escape giving you 2 assist then suddenly you are no longer behind but actually winning your lane now as well as you just made 210 gold from those assist. He is not only an effective bruiser but also has a good steroid (his E) for team fights later and a free heal/cleanse combo on himself with a short CD. With all the utility (and the ability to play any lane or jungle) no wonder he was chain nerfed for so long.
Many runes are viable on GP but I went with armor pen reds (you always want these for him really) mana regen per lvl yellows (for spamming moves especially his Q, although armor yellow is what you want if you are jungling) and cd reduction per lvl blues (being able to spam moves is good) i took health quints to make the laning phase easier but really you can stack more armor pen here if you want to do more damage or you have other options.
Masteries are pretty easy you just get offensive physical damage and extra health and you're set. You can go tankier if you want but really GP should be able to dish out some damage to be effective.
Okay so the thing about items is that they are always situational. The items I put on the build you see above are pretty much the most common build for bruisers who want a combination of damage and tankyness for getting up in there during team fights and dishing out damage while being focused. If the other team has cc that will give you problems or almost all magic damage Merc Treads are prob your best bet, if you like like to play offensively and be able to spam your gun more often (especially if you are against a passive farming champion) then boots of lucidity are probably what you want. getting crit is good on GP which is why I really like items like Zeal, Trinity, and Atma's. Warmogs just has such great synergy with Atma's that I pretty much think you should probably think of Trinity/Atmogs as core on GP. If you need MR sell your Philos and get Force of Nature or Banshee's after those instead of upgrading it.
I max Q first for generating gold or harassing then W because being able to get out of cc faster and heal yourself for more is important although you can choose to switch from maxing W to E once team fights start happening as the roids can really determine if your team wins a fight or not.
So all in all this is my first guide which is why it is so lazy, I will probably make it look nicer later with some pictures and whatnot for those of you that don't like reading. Also, I will add a jungle build and section later but just didn't include it initially because like I said, I'm lazy.