I remember Colin Webster doing a Reading game on Sky about a year or two before he retired and I thought he was excellent.
I'm not fully certain on the names but a few other officials I remember seeing having some very good games, again shortly before they retired, were Clive Oliver, Graham Laws, Scott Matheison and Eddie Ilderton.
I think it's always difficult lower down the leagues as you often only see a referee a limited number of times so have no idea what the general standard of the above over their careers was but certainly they impressed me at times I saw them.