Sorry I don't see Neil Young by himself in the top 30. All his songs sound the same, and I'm not the only one who thinks this (just ask Dana Carvey).
Any list without Led Zeppelin, Beatles, Rolling Stones, Pink Floyd (I guess, not a fan myself but...) is a list made by someone who has no idea what they are talking about.
With only 1 or 2 exceptions, any band after 1980 does not deserve to be on the list of top 10. The exceptions might hold for GnR and Alice in Chains or Pearl Jam.
NO peticular order on this but:
Led Zep
Cream - I think a large credit should be given to them for most flavors of Rock and metal after their break up.
Beatles
Rolling Stones
Pink Floyd
Bob Marley
Earth, Wind, and Fire
and personally I think Oingo Boingo is worthy of the top 25, just for the song "Insanity". Plus they have a nice mix of Ska with some generally kick ass music.
Beyond those I'm not really sure... Ten Years After could be in the top 10,as well as CSN

but not neil young by himself, Black Sabbath, The Who...