Overrated:
Theatre of Magic
Circus Voltaire
Medieval Madness (top 20 game but not best ever)
Willy Wonka
Guns N Roses (Data East)
Road Show
Centaur
Fathom
Diner
Black Knight 2000
Transformers

Underrated:
CSI
Goldeneye
Elvis
Mary Shelley's Frankenstein
Waterworld
Baywatch
Catacomb
Mystic
Medusa
Stars
Space Shuttle (it gets love but should be higher)
Munsters

BTW I think Junkyard is trash, I kept Popeye over JY when I decided to sell a pin, the only pin I've sold in 16 years. I'd say Popeye's underrated but I understand the theme isn't for everyone. Fairly deep ruleset for it's time with great DMD animations.

Totally agree on MM.

Roadshow to me is too repetitive with not enough variety. I've never played one with the Soren chip or a Pinsound, which I think would probably be game changers. But in the wild without those things it gets old because the theme can't carry it. And it seems like the ones I play are always broken.

I get the Popeye upper playfield complaint, it's one of the few (or perhaps only) upper playfields that obscures shots. But it's really only 2 shots, the two upkicker holes. And I guess the rollover lanes can be hard to see through cloudy plastic (LEDs can overcome this and be more visible). Still I think it's not as bad as most people give it grief for.