The kind that I can actually eat, for starters. I hate standing in front of the freezers reading the labels on everything, so I usually default to plain vanilla or chocolate, or chocolate with pecans.
I can't have any sort of baked good in it or risk many of the extra stuff since that means gluten. Some brands put it in there for no logical reason, like Blue Bell. Which is too bad, they make a vanilla and strawberry (with pieces of strawberries) ice cream that is delicious.