For snack bars, I like EAS Myoplex Low Carb bars. The protein to carb ratios rock, and the flavors are decent.

I've tried other bars that I really didn't like. The MuscleTech Nitro bars were just nasty (I have a friend who works there and I got a killer discount, and still didn't buy any more). The Champion Nutrition bars made me naseous just from the taste after about 5 of them (over a two week period, not in 10 mins or anything).