I have had some great ball mice... The Razer Boomslang was an amazing mouse, but for me, a tad too large.
I did have a bit of a phaze with trackballs and I still got a couple that still get used once in a while, but only because I kind of paid so much for them I want to justify paying for them kind of way.
I also have a couple of really old mice, and again they actually work amazingly, but only cos I also have a couple of Atari computers and while I have USB and PS/2 converters and I can use more up to date mice, the resolution of newer mice is simply too high for those older computers, and so moving the mouse about 1cm usually ends up throwing the mouse all the way across the screen LOL so mice with a DPI of 400 or less is often better than one with 3000+DPI