On my main Amiga I've got a Wizard Developments 500dpi 3 button mouse. Got it second hand in 1999 along with the Amiga. I bought a spare in 2000 and gave the spare away in 2003.
The original wizard mouse is still working as smooth as it did the day I got it, and I've only cleaned it out maybe twice... The switches in the buttons are still as fresh as they were in 1999. Probably the best mouse I've ever had.