So far I've downloaded Lost Wind and Defend Your Castle and I'm enjoying both purchases.
Lost Wind is sort of like a side scrolling version of Okami. You play as a kid who has to use his Wind Magic to save the world from an evil demon. You use the Wii Remote to cast his Wind Powers in a similar fashion to painting in Okami except it is in real time and doesn't pause the game while you paint. I'm finding it very fun to play and the visuals are amazing on it.
Defend Your Castle actually is based off of a free Flash Game so you can try the flash version before you buy it. The game play is the same as the flash version but they improved the graphics for the Wii version.
I thought about buying the Final Fantasy: Crystal Chronicles but decided to hold off when I saw that you were going to have to buy add-on content for it in the future.
I can't wait until Animales de la Muerte comes out. That game looks awesome! Also World of Goo and Star Soldier R look really good.
http://www.youtube.com/v/j7LR6EXx9ug&hl=en
http://www.youtube.com/v/KTdcP4LaddE&hl=en
http://www.youtube.com/v/-A_JfkzPwww&hl=en