My pick would be:

Goodbye Jumbo by World Party

A great album without any filler,every song as strong as the other, a hugely underrated classic 'halfway' Revolver by The Beatles and Sign of the Times by Prince.

Gene Clark's No Other, a weird mongrel album of psychelia, country and 70's-era bombast.

In fact, Gene Clark gets my vote as rock's most undervalued performer. Gram Parsons gets all the credit as the originator of country/rock, but Gene made records in the same era in more or less the same style, was certainly a superior vocalist, and (I'd argue) wrote better songs, but he's relegated to fringe cult status while Gram gets all the posthumous glory.
[Edited 11/29/08 5:41am]

Riverpoet31 said:

Totally agree!

"Invincible" by Micheal Jackson. Great love songs on there and not enough promotion from Sony.

damosuzuki said:

Hey, thanks!

I have a lot of stuff from The Byrds, but nothing from his solo career.

I'll be checking this out.

INXS Live Baby Live - this live album sounds so good, many of the songs are stronger than their studio versions. But this album began the commercial death of INXS - why? Still a mystery to me.

I think one of the most underrated albums of all time has to be Stevie Wonder's Hotter Than July. You probably say huh? But when you think about it, people always mention first, Songs.., Innervisions, Talking Book, even In Square Circle. But always overlook Hotter than July. Why? I don't know so that's why I'm picking that. Also, Public Enemy's debut album Yo! Bum Rush the Show always gets overlooked. True, it may not be as polished as their later efforts but a pretty good album nonetheless. So those are my 2 picks so far. If I think of anymore I'll be back.