Social Life/Party Scene at The U and advice for major selection

So UM is looking like my top choice as of now. I was accepted as a biology major on the pre med track but have heard from plenty of people to try and choose something different as my major to distinguish myself. Do any of you know if this makes a difference? Aside from that, I am aware that the academics are pretty solid all around. Now, I am a hard worker but I also enjoy a good time, so could anyone fill me in on the social/party scene at The U. Does the smaller student population hinder much? And what do people generally do on weekends. Lastly, from a purely social/fun point of view, which would provide richer experiences, UF or UM?