Google Chrome! Waits impatently for it to be released...
Probably my favorite thing about the Nexus is the browser and just how quick it is. Chrome is my favorite browser because of it's incredible speed, but I'll take this current one for now=P. I think they could improve the bookmark functions, having to tap twice and then having the folders all over the place is a bit of a mess, but the browser itself is the best I've used.
ics browser + is worth checking out from the market if you like the stock browser's side touch controls.
it gives you way more options, like direct to book marks and default to desktop, as well as page down with the volume keys. which I like.. all that's missing is the old zoom buttons. add those and i'd be set.