I could talk about those all day. Man, some of those NES arcade ports were the worst. One of the things I hated the most was the way that they'd make a completely different game sometimes. It wasn't always a bad game, but I'd always be disappointed that it wasn't the arcade version at all. They'd even write shit like "the arcade hit" on the box sometimes or in the ads sometimes.
Rygar was the one that really got my goat, because it was one of my all time favorite arcade games, but it was a totally different game on the NES though. The NES version is what most people think about when you say Rygar, and everyone loved it. But I wanted my arcade port.
I thought that Double Dragon on the NES was pretty terrible too, with the whole collecting hearts thing.
Pac-Man for the Atari 2600; I don't even have to go there.