I'm currently working on a profiling system similar to (but quite different from) the Rabbit Hole. Since I want this to be quick and intend to replace it eventually,, I'm looking to make genres and game systems denormalized - that is, there are going to be a set number of them, rather than an exhaustive list.
Freeform, Semiform, and 'Other' are three basic categories, after that I have room for 28 more. I'm currently planning on using the following list:
Big Eyes Small Mouth
Call of Cthulhu
d20 Modern, d20 Other
Dungeons and Dragons Classic, Dungeons and Dragons d20, Dungeons and Dragons 4th
Exalted 1st, Exalted 2nd
GURPS Classic, GURPS 4th
Legend of the Five Rings
Mutants and Masterminds
Star Wars Classic, Star Wars d20
Warhammer Fantasy Roleplay, Warhammer 40k Roleplay
World of Darkness Old, World of Darkness New
'Classic' refers to older editions of the most popular role playing systems with more than two editions. Since D&D represents nearly half of the TRPG market, it gets to have three categories >_>
I'm posting this for comment, if anyone things something should be replaced, if GURPS and Exalted don't deserve two spots (probably not) that could go to Deadlands and Runequest or something.
This system will eventually be replaced by something more fluid, but that's a 'new CMS, new server' sort of deal.