I was a huge fan of Super Metroid on SNES and completed it when it came out in 1994. Metroid prime is a fantastic update of the old SNES game, having all the same elements whilst updating it for 3D. All three games are huge, challenging and extremely addictive.
I would call these games First Person Adventures rather than shooters - the pace is a bit slower than a standard FPS , but as long as you don't mind a bit of brainwork and exploring to go alongside the combat these are unmissable!