In all seriousness, I was very sad to hear the news of the passing of these two 60s rock titans. The discovery of the music of these two artists, and the mythology surrounding them, had a catalyzing effect on my taste in music. Love, Barrett and The Velvet Underground formed a sort of holy trinity for me when I was in high school. One of the things that especially bonds Lee and Barrett in my mind is the fact that after an intense period of creative genuis, neither ever created anything close to as good again (in Barrett’s case he never even recorded again). Sometimes it really is better to burn out than to fade away.
No doubt both Barrett and Lee's careers were hampered by drugs and mental illness, but one could argue their careers were made in no small part due to drugs and mental illness as well. Lee's passing is particulary sad, as after years in the wilderness (including time in jail), he finally seemed to have gotten his life back on track before he got sick.
As for Barrett, beyond his music, much of his appeal to me always laid in the mystery of his total disappearance from the public eye after releasing his two solo albums. In this interesting interview Barrett's sister claims Syd led a fairly normal life, and did not suffer from any mental illness. While such a revelation might puncture the romantic image of Barrett as a wild-eyed recluse, it should be pointed out that his sister seems to be a bit protective of him. Still it’s interesting to consider the possibility that since 1980 or so Barrett lived like a normal guy with interests in gardening and photography. It’s probably closer to the truth than the mythology his former band built up around him.