Sometimes there's just something that you don't think makes sense in a gaming system. Toss your list of gaming features/mechanics you dislike, and explain why you dislike it, and maybe even a possible solution. If you don't have any, you can always comment on what other people have commented on and give your opinion on why it doesn't fail, or your agreement and maybe your own possible solutions to the problem.
Drac has asked to limit them to one system when I mentioned this thread, and since most of the ones I've got in mind are D&D, I guess I'll limit it to D&D 3.5!
I'll start off with a few that I can think of tonight.