Bunker Defense like the old Starcraft map? Those were good times.
The original Aliens Vs. Predator game had a few maps that were somewhat similar to that. The game itself lacked polish, though, so I wouldn't suggest it. Might be another reference to do some research on, though.
Left 4 Dead is loosely related. You're not defending a bunker, but you're defending an area from onslaughts of zombies. Don't expect to sit around inside and shoot out windows the entire time, though.