Firefox 3.6.7 with a couple addons to improve usability on the small screen:
Compact Menu 2
Used the same addons on my Eee 701, it's no longer cramped with them, just a bit small - websites aren't designed for 800 screen width.
Also Download Statusbar and Adblock Plus because they're awesome
Fennec is nice too, but it's designed for finger usage, and that doesn't work too well on resistive touchscreens, and if I have to use the stylus anyway I prefer Firefox.
I use Firefox primarily. Copied my profile over from my desktop all my add-ons work, bookmarks etc.....feels like I'm at home. One add-on that wont install on linux without editing the file in the xpi is Grab and Drag. That add-on rocks makes web pages finger scrollable. I don't do much flash based browsing so I don't miss it.