The most tough mouse i've got, is the "brick" which came with my A500 (with 2m cord) well maybe except buttons, but it lasted longer than 3 of 1200 mices - those with amiga logo on them - they had a small piece of metal plate with roll to tighten the ball, instead of roll with spring (the A500 "brick"), and after some time, you had to bend it, that the ball was tighten well, and pointer was moving without bounding. And after few of those operations, this piece of metal plate was stressed too much, and broke up.. Now I've got logitech mouse, and it rocks..