Sony MZ-EH1

I bought this through Audiocubes many years ago and it's been my favourite music player ever since.  It has the same sound quality as the top-of-the-line recorder (the NH1) but in a slimmer body.
 
Of course it has all the down-sides that go with minidisc - limited space, delays while it reads the disc, skipping, having to deal with Sonicstage - but when you hear the wonderful sound it makes up for all of that.
 
I hope mine lasts forever.