I have gone through so many mice i feel i have no option but to reply....
In order these are my favorite mice......
1. Original 1990's 1 button apple mouse.
Not a whole lot of features, but nothing was quite the extension of your hand as it. Weight, balance feel and accuracy were all there. No need to adjust a thing.... unfortunately for apple they moved to the hockey puck style mouse and its been a race downhill since.
2. Rat 7
Awesome, fantastic, accurate, adjustable and all. My only gripe is the lack of sidewall towards the rear area where my pinky normally wrests, no problem if you dont "claw" your mouse as I do. Build quality is top notch, comfort is top notch. Even the programming features are great. Loved the mouse so much I ended up buying the keyboard (strike 7) and think it is the cats meowwww. THis is my current home setup... strike 7 kb and rat 9 mouse (i dont like wireless or id have the rat 7).
3. Logitec GSeries (430 i think it was) mouse
I love this mouse. Id probably still be using it with my laptop had I not accidentally dragged the cable out the car door for about 10 miles.... usb cables and 60mph pavement dragging dont go well together....
4. Razer Death Addler
Great. Took my hands forever to get used to it, but once the cramps dissapated this was my goto mouse till the gSeries mouse.
5. Thermaltake TT
I havent had much time with this mouse, but i got one for my buddy to use on his rig i built for him. I really like it. I bought it because he really wanted my mouse, but microcenter didnt carry, it looked similar (which is all he cared about) and I got it. I was surprised how nice it was. I didnt expect it. After working on his computer for the setup i really didnt want to let it go. Given time I think it would climb higher on this list, but i didnt give it enough time to be critical so here it stands in last place but maybe undeservingly.
Other Razer Products.....
I really didnt even want to acknowledge the razer line in this but the death addler really is a nice mouse. As for the rest of the razer line, they suck. Ive got 4 or 5 in my closet and i hate them all. Buttons are just miserably located, weights are all wrong and i swear their mantra is simple "make it look cool". It works because I have 4-5 of them in my closet and only one ever saw real use, but as for comfort, cool makes absolutely no difference. have sworn myself off the razer product line. It is like getting used to a new torture device. Some hurt me so bad after a few hours of work, I could not go on.
Other quick notes....
To be fair I am a big handed... well actually a huge handed individual (easily palm a basketball) and work in 3D computer animation AND a heavy gamer as well so I put a lot of critical movement into a mouse. From precise slow accurate clicking to wc3 strategy clickfest gaming to fps games, i put my mice through hell and back. As for how you use your mouse, well, YMMV as always.