I use four different mouse type controllers:-
Apple Trackpad (built into MacBook Pro), I really like the gestures and I find it easy to use.
Apple Magic Mouse, I know some people really hate the Magic Mouse and find it uncomfortable. Well I'm the opposite, I tend to push it around with my finger tips and like having the sensor at the front. I find it easier to do precision work with versus the Trackpad. The gestures are nice but not as good as though on the Trackpad. However it is pretty useless for gaming.
Super cheap wired Logitech 2 button plus scroll wheel optical mouse. I use it for playing games, it does this job just fine, but I don't use it for anything else.
Wacom Graphire Bluetooth graphics tablet, for graphics work where I need greater precision, pressure etc..., though I use it as a general pointing device as well. The pen weighs almost nothing so its very easy on my hand.
I have several Mighty Mouse, they all have dodgy scroll balls where no matter how much you clean them they don't work in one or two directions, annoying.
Personally I would see if you can try the Magic Trackpad and especially the Magic Mouse before buying to see whether you'll find them comfortable to use.