I use the Weatherproof labels from onlinelabels.com...they are considerably more expensive than regular but they are made from vinyl. Therefore, they are easy to take off- one piece. I have used the regular labels from them and agree they are a b*tch to get off. If you don't mind spending the $$, the weatherproof ones are great. (100 sheets @ $60= 60 cents per sheet, 6 4x3 labels per sheet= 10 cents per label...standard white matte is 1/3 the price)
Just my opinion.