I dunno.....
if you look at games as a form of art (and I look at everything as a form of art, from playing the guitar to designing it) the idea of genres seems stupid (at least to the true artist) but then again there are certain games that will apeal to a group of people because of the similarities in the game play. In some of them (IE GTA) we'd have to be real careful to put them in a category.
I have come up with a pretty complex list or genres and subgenres:
Racing
Simulation (PGR 2 and RSC 2)
Arcade (Cruisin' USA)
Cartoon (Mario Kart)
Action (more broad than FPS)
Tactical (sneaky) Shooters(Ghost Recon, Hitman)
Large Scale (guns a blazin, multiplayer) Shooters(UT, Halo)
Fighting (Soul Calibur 2, duh)
Adventure (Pirates: Legend of Black Kat, Shinobi)
Dancing (britney spears...DDR)
Strategy
Real Time (star craft)
Turn Based (Civilization 3)
Commercial (Roller Coaster Tycoon, Jurrasic Park: Operation Genesis)
Role Playing Game
Western (Morrowind, Baldurs Gate, the open ended plots)
Eastern (Final Fantasy 7, the linear plots)
Online Massively Multiplayer (Ultima Online)
Puzzle (tetris world)
there is probably a lot I have not thought of yet, but I'm sure somebody will get to it.... also there must me a miscelanous...btw how many genres could you put vice city in? see ya gotta be careful.
also a good idea would be to have a link at the bottom of the genre list (in the same format as the genres) that shows all new(unread) reviews