Lower upper deck have always been my favorites. Great overhead view of the game, but close enough to see who is who. I had season tickets low in the tunnel end zone for years. Loved the people there, but you're basically watching the Jumbotron anytime the teams are on the other side of the 50.
Don't worry about the drunk people....they're gonna be everywhere. No way to escape it. Your best bet is to ignore and have your own fun.
Oh, and if you're worried about weather...why go to a Bills game? It's all about the experience of being there. Rain, snow, or shine, it's still a blast.