Well OpenFeint is customizable, Aqua Globs and Super Shock Football have both done it with their own theme: But yes I agree, I hope Apple does their own universal system.
I think cocosLive looks the best for this kind of solution. I haven't used it yet myself but if all you want is highscores (and not challenges, chat etc.) and you want to display them in your own way it's ideal. Basically when you make requests to the cocosLive server you get given the raw score data to do with as you please. Compare this to OpenFeint where you make a call to load up a completely separate OpenFeint interface which then handles the display of scores. And you don't need to have developed your game in cocos2d to use cocosLive
Plus+ is the best but you got to apply for that. Open Feint is slow, but has a lot of games and users making scoreboards more compettive. I would reccomend. AGON has less users but is much better than feint
Any one knows a good tutorial in creating your own leaderboard? EDIT: Anyway I tried to implement OpenFeint. It's really easy after watching that 19 minutes tutorial, and it looks great too. Plus+ has no clear way of offering their service though, I heard.
I wrote a tutorial on this. The leaderboard service offerings are pretty slick, but if you'd like to experiment with rolling your own service maybe you'll find my posts instructive. There are some definite advantages to outsourcing your leaderboard, the most attractive to me which is accessing a community of gamers culled from many different games. It's not too technically demanding to build your own, though, and full control can be quite nice depending on how unique your leaderboard's design. Part 1 Part 2