Favorites online seem to be the TC electronics Polytune, Sonic Research ST-200, and Korg Pitchblack. I'll go for anything from those ones to Behringer to Boss to GFS -- I just want something that works well. My tastes, as is well-documented, tend to be cheap. I can't see myself going much over $50 for a tuner, but that still leaves some wiggle room on used stuff.

So...what do you use? What have you heard is good? What's worth skipping over?