IMO, Pink Floyd (Waters and Gilmour) is by far the greatest band of all time, and since they are generally just rated as a "great" band, I'd have to say they are very underrated.
The Dead Weather is Jack White's new band. I have not listened to their new album but their performance on Conan was great. For some reason I got the idea in my head that they have only released their album on vinyl, but I could be wrong.
Easily some of the best musicians ever assembled in a band. Were the best touring band of the 1970s. Their longtime guitarist, Steve Howe, was voted guitarist of the year 5 years in a row by his peers in the annual poll conducted by Guitar Player Magazine. Rick Wakeman has generally been considered the best keyboard player as well.
Due to some silly politics, they aren't in the R&R HOF, but are deserving many times over.
If you like the V-Roys, you like them. Keith was a major influence on their earliest stuff. Also check youtube for Live on WEVL 89.9. Good little session.
I knew those guys. Most of the band was from West Point, MS. All those guys were great. First time I met Shannon he asked me for some mushrooms and then we went rollerblading at the old parking garage around the block from Beale. Ahhh the memories...