The first we have to mention is of course the greatest: WABC New York. 770 AM, with Dan Ingram and Cousin Brucie and Ron Lundy and all the other greats that shaped the music scene in my hometown. Allen Sniffen put it all together on the Web.
The great one in LA, which carried the late 60s after KRLA and KFWB carried the early, was KHJ. Gotta love the jingles, generated by the Drake-Chenault team. Woody Goulart has assembled a great page, ''Boss Radio Forever,'' about the history and evolution of the D-C formula (see KHJ, CKLW, WOR- FM...) and especially about the beginnings of 93 KHJ.
Jeff Roteman has a page honoring ''The Rock of Chicago'' -- Channel 89, WLS. Link here also for his KQV-Pittsburgh page.
Jack Decker's Classic CKLW Page has all the info on "The Big 8'' -- though actually based in Windsor, CKLW was Detroit's biggest Top 40 station through the early 70s.
Dale R. Patterson's Rock Radio Retrospective Alive! page has some great information about radio as it was -- lineups, ''where are they now,'' and a Hall of Fame.
Check out Uncle Ricky's Reel Top 40 Radio Archive for airchecks from many of these great stations.