From what I know (and just to pick one, for Maiden and others there are many):
Iron Maiden:
Best-Stranger In A Strange Land (though there are many more)
Worst-Futureal
Metallica
Best-Unforgiven
Worst-Unfrogiven II
Megadeth
Best-Sweating Bullets
Worst-I will need to listen to the albums I have more before answering
Kiss
Best-I Was Made For Lovin' You
Worst-not familiar enough with Kiss for that
Saxon
Best-Dallas 1 p.m.
Worst-I only have the best of and there was no song I dislike
Overkill
Best-Necroshine
Worst-Stone Cold Jesus (only lyrics wise, I don't have a worst for Overkill)
Savatage
Best-Miles Away (there are many more)
Worst-sorry I just can't pick one, I like them all
Anthrax
Best-Medusa (Joey era)
Room For One More (Bush era)
Worst-probably something off of Stomp 442 (the last Anthrax album I heard)
W.A.S.P.
Not familiar enough
Black Sabbath
Best-Sabbath Bloody Sabbath (Ozzy era)
Sighn Of The Southern Cross (Dio era)
Worst-got me