While I will agree that Virtua Cop is amazing, am I the only one here who likes Freedom Force for the NES...?
http://en.wikipedia.org/wiki/Freedom_Force_(NES_game)
I've always been a fan of light gun games, but those two are my favorites. I remember one time back in middle school when me and my friend went on a field trip to a local amusement park. It turns out it just happened to have a small arcade with Virtua Cop in it, and we played it for hours.
And I can't count how many times I've played through Freedom Force, and it never gets old to me.