My uncle's 1972 Blonde Telecaster Custom. He died when I was about 4, and my Grandma kept his guitar in a back bedroom in her house until I was 17, at which point she gave it to me. The finish was checked, and she had written his name on it with a sharpie, so I had it re-painted like any dumbass 17 year old would have done. It was a professional paint job, and looked cool, but it completely ruined the vintage value of the guitar. Even though it was re-painted, it was probably still worth some scratch, but I had no idea at the time, so when I was about 20, I traded it for an Epiphone Les Paul, even trade.
I get sick every time I see an original Tele Custom in Guitar Center for about $3200. I keep thinking, "Man, that would have bought the EBMM/EVH I've always wanted." I don't feel bad because the guitar was a great guitar or anything, in fact, it played rather poorly. The high E string would tend to slip off the bottom of the neck past the twelth fret, and the stock bridge pickup was extremely trebly. Great for country music, but not much good for what I play. So, I guess I don't really regret getting rid of the Tele, I just regret not getting out of it what I should have.
Oh well, live and learn I guess.