Naks are famous for being well built, so look out for the CR-E range, in particular the 2-E or 3-E. The more modern DR-2 and DR-10 are great but they still fetch £100- 150 2nd hand. The DR-1 is the one to get but rarely comes out below £250. However, make sure, with any of them, that they have been serviced fairly recently. Belt and head wear are a nightmare with any well used deck over ten years old. Which they all will be.
Elsewhere, the Denons are pretty good, but the modern decks were much more 'hit and miss'. The older 24' and 44' are good buys, again if serviced recently. The more recent decks DRM-640 and 650 were good but watch the price on these. They were only 'budget decks'.
Teacs higher end decks, like the 6030 are worth looking out for but the lower end decks while ok, are just that 'ok'.
The Yamaha range were great value for money, but suffered from quite a high (for Yamaha) returns level, so be careful when looking at them. The recent KX-580SE is a terrific buy sonically, but again retailed at around £250 so don't go mad.
For Sony the TCK-611S made a big name for itself as a 'budget' Dolby S deck, and is very good with tapes you make yourself. However, it's not as hot with pre-recorded tapes.
Aiwa. They make superb budget decks and offered amazing sound quality at the sub £200 level. However, they tend to have been thrashed by their owners as a result! Steer clear unless the deck is spotless. For them it's worth seeing if one the XK-S7000 or 9000 turns up. Try and get one thats been serviced though.
Overall, the best buys for recording and playback of pre-recordeds are Nak's. They may be 'manual everything' buy sonicaly they are worth it.
Rule of thumb with cassette decks though, is try and get one with a recent service behind it, a FSH (if possible), and avoid the budget decks. The budget decks were great when new, but tend to have been well used and their owners aren't likely to bother getting them serviced.