Platinum Members
Veterans
Gold Member
Gaming Moderator
Coder
Global Moderator
Admin/Owner
First of all renaming donators/vips and legendaries would be an interesting little touch. Veteran may describe better the members of the group as far as it contains old, experienced members. The problem might be that the vips might feel a bit disappointed for paying more but getting merged with the donators. So a good choice would be to rename donators to emerald members and vip to platinum members. Or the other way around.
Renaming moderators to gold member as it used to be, it will give a better taste to what gold members are, as far as they are like the simple member with just some extra permissions. Also, punishing members in any way wouldn't be available for gold members, imo.
Coders, and global moderators should stay as they are, as the describe perfectly their job. Also, only a coding rank is enough, as this forum is mostly a gaming forum rather than a coding forum.
Post based groups are good in my opinion. A good thing to do with them is to change their color name after a certain ammount of posts. Not as many as the "I see dead people" rank. Because it is almost mpossible to reach that many posts, these days as the activity has dropped a bit. You can also add some more humourous post based groups such as "Chuck Norris" at 5k posts, or something similar.