In all builds your choice of boots varies between beserker's, mercs, or tabi. I generally prefer a defense boot to the berserker's.
Standard build, good in most situations, helps blunt burst so you can lifesteal it back, has a decent mix of DPS and burst. Just a solid build all around. If you are very fed you can get a triforce early on in place of a frozen mallet. Depending on the game you may also prefer a maw of malmortius to the GA or the mallet as well.
The duelist build. Very good DPS but relatively low burst, it is also a very good build for dueling and chasing (I expect this build to be even better with the new blade of the ruined king). I take it when I want to have dueling priority on my laning opponent while splitpushing, especially if I'm ahead. I run it against fat assholes like Nasus or Tryndamere, strong splitpushing duelists, and this build helps a lot when ahead. It's also a good build if your ADC is someone who falls off against tanks late game in relative terms (like Jhin or Corki) and you want to have strong DPS in team fights late game. This build's DPS and durability allow you to function in the role of primary tank-shredder in team fights well.

Assassin Yasuo. Relatively low DPS but a lot of burst, this build can blow squishies up extremely quickly, though this build is also one of the squishier Yasuo builds, due to the lack of PD and GA (which can replace sterak's, as can a mercurial, depending on game).
These are just a few general builds as a guideline. You should alter your build depending on who is in the game and how it is going.