When it comes to rock bands, if I'm going to check them out of want a good body of work by a band that usually will feature both hits and songs for "diehards" I go with live albums. The songs are usually more raw and extended; gives you a better representation of the band's talent.
Some Favorite Live albums:
KISS ALIVE II
AEROSMITH: SOUTH OF SANITY
ALICE COOPER: A FIST FULL OF ALICE
IRON MAIDEN: A REAL LIVE DEAD ONE
METALLICA: LIVE SH*T: BINGE & PURGE
SLAYER: DECADE OF AGGRESSION
AC\DC: IF YOU WANT BLOOD LIVE
W.A.S.P.: DOUBLE LIVE ASSASSINS
BLACK SABBATH: REUNION
OZZY OSBOURNE: TRIBUTE
DIO: LAST IN LIVE
MINISTRY: IN CASE YOU DIDN'T FEEL LIKE SHOWING UP
ACCEPT: THE FINAL CHAPTER
U.D.O.: LIVE IN RUSSIA
POP/DANCE ALBUMS? DEFINITELY the studio albums since 99% of them lip sync in concert!
How about you?