SMS sucked, but SMG is the best Mario game ever. It combines the best of SMB 3 and SM64 with its own uniqueness.
Other games that are great;
MP3- Awesome controls and Boss battles
Mario Kart- Fun game with great online
No More Heroes - Brilliant
Trauma Centre - Good use of Wii controls
Brawl - Great fun with friends
RE Umbrella Chronicles - My favourite light game ever
RE4 - Classic
Fire Emblem- srpg
Up coming games http://vgchartz.com/forum/thread.php?id=34940
Myself I would not sell a 360 to buy a Wii or vice the versa.
-UBISOFT BOYCOTT!-