Blue Oyster Cult somehow kinda slips by under the radar even though they're always there and they're killer. I've seen them twice; first with Rainbow (why I was there) and then recently with Deep Purple. Both times incredible shows, and for some reason I wasn't expecting it. I remember back in the day telling someone I wasn't really into them, but then I went to my album collection and I had six BOC albums.
You are SO right about Blue Oyster Cult! I was blessed enough to see them a 2nd time, this one circa 1995 opening for the Allman Brothers. What a great show that was as well--both bands brought it!