Channon.Very big money signing & an England regular but useless for us.
Glad someone else mentioned Channon, as he was one I thought of. Wouldn't quite say he was useless - he scored 24 goals in 72 league games, which isn't a disastrous haul by any means, and he had some good games. But he was a big, big disappointment considering that he cost a record fee and was meant to be the final piece in the jigsaw, the signing who'd turn us from runners-up into champions.
Arguably we made an even worse signing the next summer, as well, when we broke the club record again to sign Paul Futcher from Luton. He in effect replaced Mike Doyle as Dave Watson's partner and was lauded by Book as a future England international. However, he managed only 37 games and was sold at a big loss to Oldham.
Slightly before my time as I started attending MR a month after he left the club and maybe a bit controversial, but how about Rodney Marsh? Playing devil's advocate to some extent. But while he was a big crowd favourite, we were top of the league when he signed, missed the title after he came into the team and didn't challenge for it again until the season after he left, and we won a Cup competition only after he was shown the door, too. He was meant to be a crowd puller, but gates were far higher in the season towards the end of which he signed and in the season after he left than they were during his time at the club.
A few people have mentioned Alan Kernaghan, and that's a decent call, too. We paid GBP 1.6 million at a time when the transfer record was under GBP 4 million, so it was a fair wedge for those days, and he had a decent reputation. He was useless.
Can't see how anyone can claim Trevor Francis falls into this category. He was an absolute thoroughbred, and his sale at a loss after only one season says more about the incompetence in the City boardroom than anything else.