NSMBWii was a good game, it just didn't quite live up to previous games in the series like Bros 3 and World which rank among the best platformers of all time.
Though they're not quite GOTY material, I feel like Dead Space Extraction, Muramasa: The Demon Blade, Silent Hill Shattered Memories, and House of the Dead Overkill deserve a shoutout. It was a good year for these underrated third party titles on Wii.