there have been many a time i hear an album the band sounds so good, and then you see them live, and you're like, wtf is going on?
which band have you made the biggest improvement on their sound, in this manner?
Well, sometimes a band sets out to make a record that doesn't really sound like they do. To these bands the record is the public face of the band, and the live shows are more of an obligation than an art form, and so they are generally pretty disappointing live.
Other bands enjoy touring and express themselves onstage more than in the studio. These bands see their records as a kind of still photo of their live existence, and you can expect those bands' records to sound pretty much like their live sets. My favorite bands were always like this: the Minutemen, Wipers, Birthday Party, and my own band thinks this way, pretty much.
There are also the rare cases of bands who change from the first type to the second, and they have an obvious cutoff date after which they went from awesome to awful. Aerosmith and ZZ Top are the most obvious examples.
To answer your immediate question, Urge Overkill.
It's also worth reading an old article of his called The Problem With Music, which is a fascinating look at exactly how record companies screw bands over.