Only 5 groups? everybody else is running rampant with their choices.
In no particular order.
ABBA (yes, that ABBA)
America (I can still sing "Ventura Highway", "Horse with no name" etc in the shower without humming)
Beach Boys
Beetles (where we would be without Sargent Pepper)
Billy Joel (hated "Pressure", until I heard it LIVE)
Crosby Stills & Nash
Dave Mathews
Eagles (Live is just soooo much better, and just think, as a kid, I thought the Eagles were boring)
Fleetwood Mac
Kansas
Led Zeppelin
Lighthouse (poor guys only had two barely top 40 hits in the 70's)
Moody Blues
Queen
REM
Rush
Simon & Garfunkel
Styx
Talking Heads
U2
Yes
Darn, I listed them alphabetical