The one that I felt recently was the death of Gary Rossington, the last original member of Lynyrd Skynyrd. Rossington was one of several guitarists in the band, and while I'm not sure which notes belong to which musician, I have read that Rossington was the one who played the slide guitar in "Free Bird".
As such he's probably one of the people most responsible for inspiring me to buy a musical instrument and learn to play. And while I really suck at it, I can at least say that learning to play has increased my appreciation for music. So thanks for that, Gary.
-k