Bioshock (does that count?), Borderlands 1 & 2, Left 4 Dead 1 & 2... I like Killing Floor but I don't like playing with strangers so I get bored after a bit lol. I love RE: Operation Raccoon City. I put a shitton of hours into it. It's so much fun. I think it's my #1 fav shooter honestly.
make money of a rehashed formula for decades to come? then yes, you are right.
UT series, anything Wolfenstein (because sentiments), Painkiller series, Bulletstorm (coz Grayson), Battlefield Bad Company 2, Gears and prolly others will pop up as I skim through my backlog at some point.