I usually just put my iPod into shuffle mode, and if someone didn't like a song that came up, they would skip it. But these artists/bands were the ones that everyone would usually listen and agree to were mostly rock, including:
Everclear
Aerosmith
Switchfoot
Red Hot Chili Peppers
Fort Minor
Linkin Park
Smash Mouth
Third Eye Blind
Matchbox Twenty
Lostprophets
Reel Big Fish
Streetlight Manifesto
Blue Man Group
Blind Melon
ACDC
Fuel
Moby
Yellowcard
Jet
Cake
Sublime
Nine Inch Nails
The Chemical Brothers
The Postal Service
Death Cab For Cutie
Deep Blue Something
The Fray
Incubus
Lifehouse
Hoobastank
Weezer
Franz Ferdinand
Dropkick Murpheys
Muse
Metallica
Evanescence
Green Day
My Chemical Romance (though only their song
Helena)
Closure
Goldfinger
The Clash
The Ramones
Eagle Eye Cherry
Wow, that turned out a little longer than I thought... 