Maybe Sam Roberts? Their influence from the Beatles is very obvious on some tracks, and they are fantastic for rocking out. Their sophmore album (Chemical City) is a little more psychedelic, with its "lost traveller" motif and great lyrics, it sets the mood right.
Jack Johnson is always amazing, but not so much for rocking out. If you want to just lay back and listen to tunes, or sit around a campfire with friends and drink and talk, I have to say, IMO, Jack Johnson is the best background music ever.
Collective Soul is always good as well. IMO, they fill in the post-grunge crap era of the early 90s magnificently. Their clean chords and great lyrics are a welcome refreshment from the Seattle grunge that overtook popular music during and after Nirvana. Check out their latest album with new material (Youth) or their debut album (Hints, Allegations, and Things Left Unsaid).
Velvet Revolver is a great band that I think is taking the right steps to bring back the bad-assness of rock, even though they seem to get a bad name sometimes (it helps that I think that Slash is a god). They are very much the sum of their parts, GN'R and STP, though I think that the GN'R-hard rock-in-your-face-attitude is more prevalent in their debut album, Contraband.
Well, those are my suggestions. I'm in your boat though, I listen to mainly more classic rock. It's hard to find adequate parallels in today's music, though it is possible if you look.