I HIGHLY recommend the Logitech G9x. Always have, always will until I find something better.
Here's a list of everything it has:
-Comfort
-On-the-fly DPI Increase/Decrease Buttons (fully customizable)
-Two Side Buttons
-Clickable and Side-Shifting Scroll Wheel
-DPI goes up to 5700 and each axis (X and Y) can be customized individually (which I strongly advise against deeming you're primarily an FPS gamer)
-Polling Rate Options are 125, 200, 250, 333, 500, and 1000.
-LED color is fully customizable
I probably left out a few things, but that's generally what appealed to me when I bought it and honestly, I don't use half of that crap. The mouse is extremely comfortable and coming from someone who you can relate to since I've played CoD4, BO, and MW3 all at a competitive level on PC, you'll love the mouse. I've pubbed Source and probably will be getting into CS:GO, and I kid you not, you won't regret buying this mouse.
Only other mouse I would give a try would be the SteelSeries Xai. I've always wanted to buy one, but my G9x hasn't had a flaw in 2+ years so I have no reason to. Please don't buy a Razer mouse though...
Good luck in your search! Post here or PM me if you have any questions!