Wii maybe more capable, but with the trash effort 99% of the companys put for wii games, i'd definitely give the PS2 the nod here. Until i see games like God Of War, Devil May Cry, Kingdom Hearts, Final Fantasy x/xii, Metal Gear, etc, the Wii is going to be the game system with the worst graphics in the past 2 gens with a handful of games that look decent (galaxy, punch out).
First, all I see you do on ANY Wii based thread is spout hate speech and trollcasm (that's troll sarcasm). Stop.
Second, you're calling Super Mario Galaxy only "decent"? That game could give 360 and PS3 games a run for their money. It certainly gives God of War, Devil May Cry, Kingdom Hearts, Final Fantasy, and Metal Gear Solid on the past gen an ass whopping.
Third you can't base the Wii's graphics on the shitty shovelware it gets. And there are third party developers that give effort. Okami is probably one of the best looking games I've played, even if it is a port (yeah, of a PS2 game). MadWorld was made with brilliant graphical style. The Conduit totes the title of best looking third party game (that's supposed to look realistic). Other games like House of the Dead: Overkill look good too, and if you look at some screenshots for the upcoming games The Grinder and Gladiator AD then you'll see.