DeathAdder! Most comfortable mouse I've ever used and I've been through various Logitechs, a Sidewinder and other Razer mice. Now on my second DA (3.5g) and couldn't go back to using anything else. It's also got a fantastic sensor.
I've had the Deathadder for 2 years, it's been a great mouse but I'm open to other things, I think I'd like to try something different. That's the reason why I created a thread really, otherwise I would have just bought the Respawn already!
As for shape etc, deathadder is great but at work I use all sorts of mice and I'm sure I could get used to a different one. I think one with a bit more weight than the Deathadder would be good to try.
Cheap option:
Logitech MX518
Safe option:
Razer Deathadder Respawn
High spec option:
CM Sentinel Advance
Let's generate some pros and cons!