The Sony WM-DD9 or the D6C or something similar. I have one of the later classics, but the problem with every tape player walkman I've had, is that when you hit the 'reverse' tape button, the tape always sounds squiggly. You can pay around $150 for one of these (or more), but the quality is something.
Granted, that when listening to Tori Amos, this actually improves her voice.
If you are after a quality miniaturised deck, the Onkyo K185 or the larger C-611 are fabulous pro-quality decks with Dolby B and Dolby C (remember those?

) and HX-Pro sound too. The sheer beauty of analogue music really comes to the fore with these kinds of decks. Nothing like putting your 2010 music onto tape to play - hear the sheer difference in warmth. None of that siblance and sharp edged high pitched stuff from CDs. They have superior definition compared to any portable walkman, but if you want to go portable, everyone knows that Sony Mini-Disc or Hi-Minidisc is the way to go
