What's your favorite game you never hear anybody talk about?
Mine has to be Dragon Quest: Rocket Slime, a DS spin off of the Dragon Quest series that sees you playing as a slime operating a tank and rescuing the people from your town. You run around the overworld, collecting items to use as ammunition and saving money to upgrade your tank. The art and music are just as great as you'd expect from the Dragon Quest series. It made fantastic use of the DS's dual screens. It's also written for a younger audience, so a lot of it is just really silly and fun! Try it out for sure, I'm so sad there's no sequel :(
Star Wars Republic Commando! Every now and then people talk about it, but it is a shame it isn't mentioned more. I actually just replayed it, I'd almost say it holds up today with the remaster mod and the rc patch.
There is also a very cool mod called "slightly remastered" which adds stuff like 3rd person scripted animations and scripted kill cams, it makes you feel like a badass!
Aside from that, I'm also surprised nobody in the boomer shooter enjoyer crowd talks about Cube 2: Sauerbraten, which is a very fast paced arena shooter. The only server that is consistently active uses one shot rifles that have enough recoil to do trick jumps, very fun to hop on for a few hours