Best - Super Mario Bros. (3 is a very close second, the tie breaker, SMB was the first game that scrolled! you had to be there to understand the impact, it was just so amazing!)
note* because of how Defender and later Empire Strikes back operated I don't consider them the same thing, they didn't scroll objects apeared on the one screen, it was a well done trick/concept..
Worst - SMBL 2 6 Golden Coins , Marios jump was way to funky.
"Let justice be done though the heavens fall." - Jim Garrison
"Ask not your horse, if ye should ride into battle" - myself