Most underrated Senator

[TheresNoMoney]

Byron Dorgan is one of the best.

[sethm0]

 Another vote for Jack Reed. Humble, hard working, and by far the most credible voice among congressional Democratc on on national security.

[socaldem]

I have to agree about the wonderful, wonderful North Dakota delegation. 

I think Colorado's junior senator Ken Salazar is great, though he's not necessary underrated except when compared to fellow freshman Obama.

I'm going to go out on a crazy limb here, though, and suggest that crazy right-wingers Sam Brownback and Tom Coburn are underrated by the left.

Why?  Yes, they're wingnuts, but each stands up for his principles in contrast to the general corporate whoredom of the unthinking Bush-supporting Zombies that populate the more conservative ranks of GOPers...

Brownback, imho, deserves kudos for his willingness to stand up for humanitarianism, particularly as it applies to helping developing countries, as shown by his leadership on the Darfur issue.  I think he also tends to definitely shy away from the veiled racism that is popular in some gop circles and appreciate his stance in support of immigrant rights... I think his stance on social issues is impractical to say the least...

Coburn, meanwhile, deserves credit for being a pain in the rump of the GOP majority and of Ted Stevens in particular.  I disagree with him on his opposition to big government when the largesse is used to help the less fortunate, but when the GOP is in charge, the largesse goes to malevolent interests and his attacks on their governance, thus, makes him a sometimes ally of the good guys... (kinda like Ron Paul)

[Mr. Paleoconservative]

Coburn, Kyl, or Sessions.