I've started with Doom (Dehacked) so long ago, then I modded Quake, then Duke, and soon I was learning how to mod other games pretty fast.
I've modded Treadmarks, Tribes, Half-Life and Q3A, however I can make player models as well for plenty of games :O
What other games have you modded before?
(Oh i'd mention Heretic if I modded deep enough - all I did was turn the transparent puffs/smokes etc to big large colored boxes for "area fogging". Looked awesome at times.)
Currently, Quake1 modding is my favorite thing to do <!-- s;) --><img src="{SMILIES_PATH}/icon_wink.gif" alt=";)" title="Wink" /><!-- s;) --> also i'm starting to replace everything in Duke3d to something completely new, different, and well....crappy. Still, nobody's played a great FPS game with crap art and sound so it's a totally unique experience <!-- s;) --><img src="{SMILIES_PATH}/icon_wink.gif" alt=";)" title="Wink" /><!-- s;) --> It's a work in progress tho.
[img:29585100]http://www.planetquake.com/gargoyle/dukebob3.jpg[/img:29585100]
Stuff will be wacky here. Pr0n mags will be cake recipie books, strippers will be soda machines (yep, something else to put your money into), and RPGs will be rocket pistols, sort of inspired by Bionic Commando (NES)'s rocket launcher.
Of course sound will be replaced also, expect something along Strong Bad's "The system is down" techno when you enter the bar <!-- s;) --><img src="{SMILIES_PATH}/icon_wink.gif" alt=";)" title="Wink" /><!-- s;) --> Of course my voice will probably replace the cheapoh oneliners. Midis are also replaced and I am sterile. You are getting warm - oh i'm sorry, it's the cheese that is. <!-- s;) --><img src="{SMILIES_PATH}/icon_wink.gif" alt=";)" title="Wink" /><!-- s;) -->