I'm trying to give up soda, any good alternative beverages out there?

I'm going to be going to college this upcoming fall and I'd like to prepare myself for the 3 buffet meals daily lifestyle. I've already got a good diet plan from my fitness instructor and in addition she told me it would be great if I could drink less soda. I drink a considerable amount now "average 3 cans a day" and my favorite part about it is the burning sensation when it goes down your throat. Are there any other healthier beverages that produces this burn that doesn't have a lot of access sugar or alcohol? Also I've heard that switching to diet might be a good option but that it might cause cancer, is there any scientific basis to this or is it just rumor?