not gonna recommend any games to you just yet cos you've plenty to be getting on with RE4, Z&W and all of the recommends in this thread (but hey you've gotta play Zelda and SMG).
I had seemingly the same problems when first got my wii online where the connection kept dropping but I had a cheap Belking router and it was actually a model Nintendo didn't recommend.
In the end I assigned a static IP address to the Wii and set the thing up manually and it's been great ever since.
*Little tip (obvious I know but) - if you do choose to attempt to set it up manually like I did then ensure you add a new connection and dont edit the existing as it's always good to keep a working one.
Here are some useful links:
http://wii.nintendo.co.uk/68.html - error code lookup
http://www.nintendo.com/consumer/systems/wii/en_na/onlineWirelessRouterIncompatible.jsp - incompatibile router and issue's with some ISP's
But hey I bought mine at launch and a lot may have changed with Wii firmware updates an all that.
