I've got Metroid Prime mapped perfectly to my PS3 controller, I love the controls in that game.
Wouldn't the lock on be very distracting? Or can you turn that off/'blind-fire' everything? I don't remember.
I believe Metroid Prime trilogy lets you play MP1 and 2 with the MP3 controls, and that would map fine to KB/M. I much prefer classic MP controls though, from my experience with MP3.
scitek, are you using the widescreen hack in Metroid Prime? When I do it, I see things load in on either side and it's too distracting to keep on.
Also have Super Mario Galaxy 2 mapped to my ps3 controller, works great. I have the right analog stick emulate the cursor, which gives the very minor annoyance of having the star icon in the center of the screen whenever the stick is neutral. Rock solid 60fps/perfect sound at 3x native resolution... WOW.