I played the original Contra games on the NES and SNES as a kid, and love them. I was surprised to learn that the series had been revived on the Nintendo DS, and it's pretty well done IMO. Contra 4 seems to capture the spirit of the SNES "Alien Wars", and extends it a good deal. Great fun, and some of the finest 2D graphics I can recall.
http://www.konami-data.com/officialsites/contra4/
