Heard ZZ Top referred to as "a little three man band from Texas that sounds like a whole stage full of top rock performers". Have to agree.
Seen em in about 1977 -- Lakeland FL.
Other acts I've seen:
Pink Floyd 1994 (without Roger Waters but still awesome!) I see that Rick Wright died a few years ago not long after Sid Barrett, the band's original guitarist and founder.
Yes (totally awesome)
Charlie Daniels
J Giles Band
Rolling Stones
38 Special
Cool n the Gang! (on their 30th aniversary)
Barry Manilo
Righteous Brothers
Neal Diamond
Billy Joe Royal
Allman Bros
B-52s
George Jones n Tammy Wynett (together!)
B B King
others I can't remember. . .