Knowing how huge SYM is, I wouldn't be surprised if this has been shown before. As I've seen this on a few other boards which have led to a few interesting discussions.
1. I would have to put The Jimi Hendrix Experience at the top. Not only were these guys revolutionary for their time, there hasn't been anyone like them since. Also Purple Haze got me learning to play the guitar, but I can't play like Jimi
2. Eric Clapton would be one of my fave musicians, he's Sunshine Of Your Love is a song which has stood the test of time. And Tears In Heaven, the unplugged version is just magical.
3. I grew up listening to Smashing Pumpkins so it was a shame when they broke up. However their music lives on, in my stereo at least.