I'd been thinking about Ninja Gaiden, but upon further reflection the game is probably too difficult for me. I play games to have fun, not be mired in endless frustration, and I hear NG is very tough. But it's got great reviews.
I don't put an immense stock in reviews til I can get opinions from *real* gamer. Xbox Mag says Riddick is the best game ever made for the 'box, but I take that with a grain of salt as they're "official", although I almost always agree with their reviews. Oh well, hopefully someone here has played it and can chime in. Bubba or jqp, perhaps?
