All depends on your era I suppose, all time bets then obvs Dixie, Bally etc, best signing as in didn’t see it coming was Reidy and big Nev, Reidy was a wreck when we got him ( as was Andy Gray of course) and nobody expected him to make the impact he did. but for me Neville was the one, absolutely underwhelming signing, turned out to be possibly our second best ever player ( people will argue for Bally, but Nev was world class for longer ( for Everton anyway).