My favorite artist of all time would be Jade Valerie (of the musical classical-meets-pop projects of Sweetbox, Jade Valerie, Saint Vox, Eternity..)
But if she were to quit music, my next favorites would be Mikael Akerfeldt (Opeth), Steven Wilson (Porcupine Tree, Bass Communion, Steven Wilson, Blackfield), Cradle Of Filth, Novembre, Marilyn Manson, Lady Gaga, Serena Ryder, Ladyhawke, Green Day, My Chemical Romance, Pink, gosh there's really a big, varied list.
And to the poster above, I've worked on My Chem's tour transportation management before, sadly, I didn't get a free ticket to any of their shows. However, someone gave me the special box edition of The Black Parade as a present once, I absolutely adore that album. It's very classic, I was thrilled over the obvious oldies-homages throughout. But My Chem's a surprisingly talented band in general, as flamboyant as their image is, and despite how many additive fans they have, they truly do make very good music; Lady Gaga and Marilyn Manson are the same way. Always a very grand talent throughout, true performers.