I don't always drink beer when I smoke a cigar, but when I do, I prefer Dos Equis.
With the recent thread bump, I thought it was appropriate.
Seriously though... Bourbon, Scotch (all whisk(e)y's for that matter), rum, beer, coffee, water, and soda all work fine for me. Rarely, but occasionally, I'll eat while smoking. Usually it's at a cookout or something similar (like a herf at TriShield's...man the food!).