Super fast page loading. Built-in BitTorrent. Plus pages that actually load properly, no built in ads, mouse gestures, OS X-like widgets, the assumption that you actually use tabs instead of seperate windows, pop-up blocking, zoom, a list of the top ten sites you visit when you click on the address bar, and all that other nice stuff.
Now if you'll excuse me, I'm going to go use the $100 Opera just paid me to go and make sure the comparison in the thread title is accurate.