well like the name tells you this is gonna be post about legendary guitars, witch are played by legendary guitarists.
So please post info about guitars/guitarists with a one-off instrument, pics are welcom!

So I'm gonna start:
Player- Brian May(Queen)
he built his guitar with his dad 40 years ago out of a old fireplace, he only spent 18 pounds on it couse he bought 3 burns single coile pickups( which now cost 200 pounds couse they have his name on them!) So he still uses the same guitar, but now he has opened a company (Brian May guitars) witch manufactures replicas of his instrument.
Player- B.B. King
Guitar: Lucille- In the winter of 1949, King played at a dance hall in Twist, Arkansas. In order to heat the hall, a barrel half-filled with kerosene was lit, a fairly common practice at the time. During a performance, two men began to fight, knocking over the burning barrel and sending burning fuel across the floor. This triggered an evacuation. Once outside, King realized that he had left his guitar inside the burning building. He entered the blaze to retrieve his guitar, a Gibson acoustic. Two people died in the fire. The next day, King learned that the two men were fighting over a woman named Lucille. King named that first guitar Lucille, as well as every one he owned since that near-fatal experience, as a reminder never again to do something as stupid as run into a burning building. Gibson and Epiphone now manufacture Lucille ES-345's.
Player:Ulrich Roth( Sorpions( former))
In the 1980's, Roth commissioned construction of custom guitars with additional frets (32). He called them Sky guitars and used them on his last Electric Sun album Beyond the Astral Skies (which was dedicated to Martin Luther-King and to Roth's fans), released in 1985. Since then, Roth entered a new phase of creative work, composing a.o. four symphonies and two concertos, and sometimes performing with symphony orchestras throughout Europe.
Steve Vai's triple neck JEM.
Custom made by Ibanez.
Top neck - 12 string
Middle - Regular JEM
Bottom - Fretless w.sustainer.
Used on the G3 Denver DVD (the name of the song escapes me)

Paul Gilbert's reverse Iceman
Custom made by Ibanez.
A reverse Iceman, made out of Korina, with two humbucker pickups.
paul photoshopped it and sent it to the LA Custom, they made it real pretty much.
ZZ Top anyone? they had like millions. Pink Fluffy, Car ones you name it they had it.