Soundgarden and AIC are probably in my top three along with Zeppelin.
My tastes are pretty much the same as yours, Scott. While not as big a fan of PJ as you, I do listen to them. I really would love to see them live, but nobody really wants to go
As for bands not mentioned:
I've seen Aerosmith three times (with a possible fourth this summer) and have never been disappointed, although I did enjoy the arena show (Worcester Centrum) more than the two outdoor shows, but I think that had to do with acoustics. My wife absolutely loves Joe Perry.
Metallica: Never saw them live (and don't want to pay big bucks to see them tour with Limp Bizkit and the tool of all tools, Fred Durst) While many people bash their records post And Justice for All, I actually enjoyed them. They've grown as artists and change styles. While the speed metal style of MoP and RtL was great in its own way, so are their other albums. And I enjoyed S&M immensely.
And now for the guilty pleasure artist:
Bon Jovi: IMO, just go old fashion rock and roll with catchy lyrics. Even if you're not a fan, I can bet you can see along to at least one of their songs.