Massively Overpowered has an article up titled: THE DAILY GRIND: WHICH MMO HAS THE BEST EYECANDY? Readers are contributing screen captures. Surprisingly only a couple of images surpass what we have in Second Life™, at least in my opinion.
I decided to put some of my images from SL up in a comment. From following people on Flickr I know there are people with far nicer images.