Numark 1002MK2 - Bought new, no complaints as a beginner mixer. Ate faders pretty quickly.
Vestax PCV-17a - A lot people love these for house/techno. Worst mixer I've ever owned. Scratchy pots that constantly needed tightening, cheap plastic knobs, terrible fader. Chrome finish was impossible to maintain. Turned me off of Vestax for life.
Pioneer DJM-300 - Great piece of kit. Simple, solid build. Maybe I just got a good one because I've never been impressed with the build quality of the 500/600s I've used, but they've mostly been club mixers that probably have several years of beer in them. Should have kept it but was cash-strapped at the time.
Allen and Heath Xone 32 - Wow. Wow! Couldn't justify owning such an expensive mixer, so flipped it. Perfect.
Numark DXM-06 - My most recent purchase. A bit of a tone suck, but has seen several parties with no complaints.