Crikey, I've got over 40 seasons to choose from.
Overrated, Ray Atteveld (90's), came from Everton for a tidy fee at the time and was bloody hopeless.
Underrated, Jimmy Mann (late 70's when we were in D1). Great player with a rocket of a right foot and a big piece of the best City side I will ever see.
Having been watching since the early to mid noughties...
Overrated - Michael McIndoe, general memory of him as a left winger was him wandering off and leaving McAlister to deal with 2 on 1's.
Underrated - dare I say it.... Lee Johnson, I'll start by saying he wasn't a great player at championship level however he was no where near as bad as a lot of our fans made out and remember him being. He and Elliott just clicked in CM together and was a partnership that worked.
Don't think a lot of Preston fans appreciated how good Paul McKenna actually was until he left.
Richard Cresswell used to get a bit of stick too despite banging in over 50 goals for us and working his bollocks off every week.
Over-rated
Billy Jones was bummed by a lot of our fans despite being run-of-the-mill for 75% of his time here. He was athletic which got him a move to the Prem and he was one of the few good performers in our relegation season but he was a massive downgrade on Graham Alexander. Tyrone Mears was better than him as well.
Most underrated
Chris Morris from the 80s was forced out due to the booboys. Went onto have a great career both domestically an internationally
Mark Bright, top scorer for several years. But played alongside sir David Hirst so wasn't appreciated anywhere near as much as he should have been.
Most overrated
Alot of our fans rated Gerald Sibon, to me he was a lazy, overrated, overpaid waster. Who turned up 1 in every 10 games.
Most disappointing
Wim Jonk, Andy Sinton and Andy Hinchcliffe were highly regarded prior to signing.
They all soon got found out though.
Ashley Barnes for underrated - even when he scored 20 goals in our L1 title winning campaign he had plenty of detractors. In the same way Sam Baldock is still under-appreciated by a portion of our fans, it tends to be the strikers who put in the graft and create space for a more prolific partner (ie. Murray), whilst grabbing fewer headlines themselves. Dale Stephens was pretty underrated up until recently.
For overrated, Vicente for all his genius on the ball often made the team as a whole less effective. Everything had to go through him and it made us more predictable. (Still the greatest player to ever turn out for us, mind). Also Beram Kayal, whilst I love him still, is a long way behind Stephens these days, and for all his drive and energy in the middle, he just doesn't have much of an end product.
Overrated: given how hard on our own players our fans are, this is tough. I'll go with Dave Livermore who always seemed popular, even winning our player of the year once or twice. I thought he was dross.
Underrated: Seems weird to say this, but Teddy Sheringham. The abuse he used to take for being slow and "lazy" was ridiculous.