I think Megaman 9 is inferior to the NES Megamans, the level design is much weaker and the music is a mess.
Defend your Castle got pretty damn boring for me, it starts out boring, ramps up a bit and then gets boring again due to repetition.
Well then, my recommendations:
NyxQuest: Just. Buy. It. Don't bother looking at LostWinds because NyxQuest is just way better.
Toki Tori: A great puzzle game (as in "use your brain to succeed", not "match the colored things as fast as you can").
Onslaught: A swarm FPS. Controls very well and is just plain fun.
Water Warfare: An arena FPS. Don't be scared away by the childish theme, it's a proper FPS with online and all. The items unbalance it somewhat but only in some modes.
Swords & Soldiers: Awesome 2D RTS. It seems shallow in the campaign but once you go into skirmish or multiplayer the depth comes through.
Space Invaders Get Even: It's 2000 points, the DLC is pretty much mandatory (they originally wanted to sell the game at retail) but it's a good game with plenty of fun. Make sure you try to go for a high score, that's when the real game comes into play.
Wild West Guns: A more elaborate version of the Wii Play shooting gallery with a western theme, my sister loves it.
Onslaught. Its wiiwares first fps its okay, but it shouldnt be considered a FPS as the only thing you do is take on swarms of insects that come at you from around.
How's that not an FPS?