I’ll start off with this album. A band with left wing, anti-nazi, anarcho punk sensibilities but I don’t think this album (or the band themselves) ever got the recognition it or they deserved. Pointed lyrics and great harmonies but the main thing is the really catchy tunes.
Chumbawamba - Swinging With Raymond
Anti Nazi tune - The Day The Nazi Died
Foxing - Dealer
With respect to the previous post. Ideally - post youtube links of albums so we don’t have to go searching 
Porcupine Tree - Fear of a blank planet.
The Jayhawks Hollywood Town Hall
Not a stinker on the whole album.
“Fun?” by the Candy Skins should have been one of the best-selling albums of 1993, but sadly, it wasn’t. 
It was in heavy rotation on my local college radio station, and it sounds just as good now as it did back then.
The single, “Wembley”, has a terrible video. That didn’t help matters.
"Everybody Loves You" "You Are Here"
anything by bad religion or social distortion…
Big Star in general should have been bigger, but their first two albums (#1 Record and Radio City) come immediately to mind, with tracks such as “Thirteen” and “September Gurls” and “Don’t Lie To Me” and “Life Is White” having been tailor-made for radio and movie soundtracks.
Tasty by Good Rats. They were a Long Island band with a NY/NJ following, but limited popularity the farther from New York you got. Tasty didn’t have a wasted cut on it.
I always thought that Permanent Waves by RUSH was great but overshadowed by the great albums Hemispheres and Moving Pictures.
Emitt Rhodes. His self-titled album was the perfect pop rock Songbook, without a weak track anywhere. Any of the songs could have been a hit single, but the record Company botched the promotion and stupidly wrecked his career.
Roots by Sepultura is widely known, but massively underappreciated. It’s probably the best heavy album of all time.
I would throw out there a band that is relatively not known to the mainstream and they are 3 who released a album call The Ghost You Gave To Me.
fg
The best rock album recorded thus far is relatively unknown: Refused - The Shape Of Punk To Come
If you ever see a copy of History of American Rock and Roll by Combine, grab it!
Ditto for The Brains eponymous 1980 debut.
And of course, the finest gem in my collection: Trees of Mystery’s Mooks On Parade.
Excellent pick, Art. Also excellent username/post combo!
I really like their 1990 album “Presto”, which is MHO their most radio-friendly.
‘How Dare You!’ by 10cc is amazing and barely considered any more.
MiMBand: Swimming Pool Q’s
Album: Blue Tomorrow