2D rocks and I'm in the camp that just doesn't care about modern systems and 3D too.
The Neo Geo is an incredible gaming experience. I've had several throughout the years (arcade MVS machines as well). They sure maximized the processing power in that puppy. There's even a 68000 in it IIRC. Both Baseball Stars, League Bowling, Last Resort, Metal Slug, King of Monsters, Umm... I'll just stop there. There's waaay too many great games for it, although you can have all those generic fighters they kept pumping out in the mid 90's. Yuck.