New Super Mario Bros. was pretty good on DS, however I liked the Wii version even more so.
The game is more or less the same concept though. Except they add real multiplayer co-op that was promised with the DS game but was never delivered.
I really liked the new power-ups than the multiplayer though. The controls were pretty good, except some various uses of motion control at certain parts. Think Super Mario Galaxy if you don't know what I mean.
Plus the level design was much better, and harder than it's DS counterpart. The game is completely original from the DS game, it is no remake or port. It's one of the best Wii games you can get for the system.