I thought this video was quite proper for the 100th post on the site. Why? well, here's a cover of Radiohead's "Paranoid Android" featuring guitar (solos included), vocals and keyboards... done by a single guy!
acidreign4470 starts off by playing rhythm guitar and singing, quite well, I might add; then moves to the solos, still doing vocals; jumps* to keyboards to do the piano part, still with vocals; finally, jumps** back to guitar to close the song...
...and I got tired just describing it.
*The use of the word "jumps" is a figure of speech, he doesn't actually JUMP from one to the other.
**See above.