They're all great characters IMO... 'Cept Silk Spectre.
Rorschach: Memorable Quotes, and his fighting style

Nite Owl: I could really relate to him...
Comedian: He showed how heroes aren't all black and white, just a whole lotta grey.
Dr. Manhattan: Blue dongs. Need I say more?
Oh yeah, Apocalypse Now parody would've been so much better had Manhattan been naked. The sheer ridiculousness would've been too much for me.
Didn't like Ozymandias for the reason that he was overpowered. Sure, Manhattan could've destroyed the world, but he was a superhuman, so that was different. This guy, a mere HUMAN, takes on three Watchmen and pwns them all. WTH?