The two main makes around here are Logitech and Razer. It all comes down to how you hold your mouse and what is more comfortable to you.
The Logitech mice are mostly made for right-handers. The extra buttons are very well located for the most part. Their mice usually come with weights so you can adjust their feel.
Razer's mice are ambidextrous. They are very light and lend themselves to a finger grip. The profile of Razer's mice shows that they are tall in the back, as this "mound" fits into the palm of the hand and the fingers laying down the length of the buttons. The additional buttons are not as ergonomic as Logitech's buttons, but are completely programmable.
I can't speak for the DPI of the Logitech mice, but I can the Razer. The Lachesis is the current top model, and it can run at 4000DPI. The Mamba, due out any time, is a wireless/wired mouse (you can run it wireless, or pull the chord from the base and hook it to the mouse to charge while you play), and it can run at 5200DPI.