My parents were fairly strict, so I didn't get to go to rock concerts. The only concerts I ever went to as an adult were Kenny Rogers and Chicago.
I didn't even have an interest in classic rock until my wife and I started dating, so I got to discover Queen, Zeppelin, Styx, ELO, ELP, BTO, Bob Seger, Boston, Kansas, AC/DC, .38 Special, Argent, Lynyrd Skynyrd, Aerosmith, Bad Company, REO Speedwagon, Black Sabbath, Blue Oyster Cult, Fleetwood Mac, The Eagles, Chicago, CCR, Hendrix, Grand Funk Railroad, Journey, Steve Miller Band, The Allman Brothers, The Who, The Guess Who, The Black Crowes, Van Halen, Tom Petty and the Heartbreakers, ZZ Top.....as an adult, all on their own aesthetic awesomeness.
My first rock concert was this past May.
Saw Styx, REO Speedwagon, and (for some twisted reason) Ted Nugent.