Halo 2 got me into violent, gory, and shooter games, though Rooster Teeth's Red vs. Blue got me into Halo overall
Halo in general got me into glitching and exploring video games
Blockland got me into modelling, scripting, and texturing, it's community made me into a better person and i made lots of friends and acquaintances
Garry's Mod got me into more detailed modelling, texturing, and working with materials
Anything i've done in games i've not wanted to imitate in real life, so i've got nothing to say along those lines...