Radiohead is #1, far and away, and seeing them this summer will be the musical highlight of my life
(unless I can somehow see the full Wu back together complete with an urn of Dirty's ashes)
Other than that:
The Beatles (Lennon and McCartney was the best songwriting duo ever, even though a lot of their stuff was done separately)
Nirvana (Cobain's lyrics were whatever, Dave Grohl's drumming.....lawd hammercy)
Pearl Jam (neck and neck for "best concert I've ever been to" with The Roots, who is also in this list if we're counting them)
Metallica (if I ever need to get amped for something, "Master of Puppets" is my go-to joint)
White Stripes (strangely, Meg's off-time drumming may be my favorite aspect of them)
Black Keys (starting to slide a little, tho)
Foo Fighters (No one writes a radio song without it being cheesy like Grohl Da Gawd)
Chili Peppers and Guns N Roses, I don't know what to do with because I love a lot of their stuff, but they can also be straight up bootybuttcheeks. "Californication" and the "Use Your Illusion" joints are up there with my favorite albums, but I could do away with a lot of the rest.