Wow, I have trouble picking a favorite album. Favorite beat?? My answer would change every day.
But to be fair, if I were to pick a few based on their historical importance or whatever, some of these come to mind (no order)
TROY - Been mentioned many times and hard to disagree with. This shows how a rap "beat" can become more than just something that comes out of an SP 1200. This track is pure beauty on several levels.
Planet Rock - I'm surprised at how nobody has mentioned this song. Seriously, this kicked off the craze with sampling Kraftwerk and electronica in general. This basically was the predecessor to G-Funk.
Let Me Ride - I think this goes above Ain't Nothing But a G Thang since it really defines the Dre sound best, with the high pitched synths and famous Parliament break. Also, it uses Funky Drummer, of all things, showing that this track has all the elements of what hip hop was to be defined for the entire west coast for over a decade.
CREAM - Yeah, it's really that amazing. It isn't terribly defining of the Wu Tang sound though, with its lack of Kung Fu-ness, but this is still the group's magnum opus song.
Shook Ones II - Yeah I don't really need to explain this one. It's the just the single most badass beat ever made.