I made the switch from beer (and not the 100-calorie kind...I liked dark, thick, heavy imports!) to wine or vodka tonics. I switched to wine for heart health, and I've sort of become a foodie and wine just goes hand in hand with that. I also like the vodka tonics because they seem to pack quite a punch. I think most drinks/wines are going to be 100 or more calories per serving, tho.
If you truly can't do without the beer, Becks Light is only 64 calories and tastes extremely close to the regular kind.
Cheers