I think Contra is great, however the only Contra games I have are the two for the original Game Boy, Operation C, and the port of Contra:The Alien Wars which was originally an SNES game. Actually, I do own the SNES original of that on the Virtual Console, but I'm not sure that counts. Both games are good, but overall, I think Operation C is the best of the two. Operation C I think is also the easiest of all the Contra games I've played in my entire life (I can beat the first level without dying! I haven't been able to do that in other Contra titles!) The Game Boy port of Alien Wars is also very good, but it's also flawed a little bit. One thing in particular that annoys me is the lack of Super Game Boy enhancements. The only major enhancements are color at the title screen, and the 5 in the Factor 5 logo is red. There's also some 16 bit sound effects when played on SGB, but why couldn't they make the music SGB enhanced too? It doesn't even have a custom border like other SGB enhanced Game Boy games! I never played the GBA port of Alien Wars, so I can't comment on that, however I did hear that the overhead stages were removed, and there were also some levels from Super C added.