I'll give another 1 up to Dolphin HD. It was one of the first apps I installed on my new N1. I really like the gestures plus you can customize your own like drawing f to go to facebook or G to goto Google search.
Dolphin HD for now. I'm keeping the older version for the Youtube download capability. If you've already updated, you might want to try the Youtube ripper that IzelTokatl posted. I haven't tried it yet.
Fennec is great too, only because it lets me log on to certain public free wifi (the ones that redirect you to a "Terms of Agreement" page before you can start surfing).