It's been done a thousand times but I wanted to give it a shot because I'm curious to what people are going to say on this site compared to others. I would go with blue album because Only In Dreams is my fav weezer song.
Pinkerton is my fav cos i feel more attached to it. But some of the songs on the blue album are their best (especially sweater song and the amazing music video that accompagnies it) but yeah I'm basically voting Pinkerton