For eating purposes only, nothing beats a first year deer. I personally don't think there's much difference in a doe or a buck when it comes to tenderness or taste. An old doe and an old buckare just about the same when it comes to being tough. If I only have one tag, as in Missouri for example, I'll go for a buck... not only for the antlers, but for the size and amount of meat. If I have quite a few tags, then younger does are definitely on the agenda.
The bigger the better? Only in the amount of meat they provide in my opinion.