I've owned various decks, but aside from an Akai and an Aiwa (sp?) the others were Nakamichi.
Of the Nak's (250/350/550/600/700ZXE) the 700ZXE was by far the best (think the 250 was payback only as I used it in my car).
This said, I also made extremely good recordings with VHS (3-head) and Sony Betamax decks.
I assume that parts for the Nakamichi's would be more readily available.
DeKay