Comparing Contra on the NES and the original Arcade version was a very fun experience. I'm still a bigger fan of the NES version, but the Arcade version was really good too! Check out some of these differences that I found.
Bet you've never seen THIS on the Internet before: a LET'S PLAY SHOW.
Anyway, I basically play a bunch of old games--both classic and not-so-classic--all the way through. Sometimes it goes well; sometimes I suck at games. Either way, I hope it entertains you!