My oldest brother (19, has a PS2, for college) only plays sports games.
My second older brother (16,has a PS2) plays mostly RPGs and Wrestling, and loved the NES but thinks that everything after that Nintendo sucks.
My younger brother (11,has a DC) plays all kinds of games, mostly sports and platformers .
My mom doesn't touch anything unless its Super Mario Bros. on NES, and not even the all-stars version, she says there's to many colors.
As for my dad, basically anything racing, mostly Nascar.
Cousins.... only my younger ones (9 and 11) really play games but all they have is Spiderman and Kingdom Hearts.
And as for Grandparents (71, 76, 81, 83), well they loved Gameboy Camera, and besides that, nothing.
As for ME (15) theres Gamecube, N64, SNES and Gameboy Advance with about 50 games in all. PLAY ALL THE TIME.
And my older brothers had an NES and Genesis (both broke, so sad) when they were younger.