Was there one song that hit you so hard you, or you liked so much that you decided to pick up a guitar?
For myself it was Boston "More Than a Feeling" Of course back in the day when I was a kid everyone wanted to play Stairway to Heaven and Dust in the Wind.
Sometimes when I'm feeling evil I go into a music store and play the first measure of "Stairway", just to see the clerks cringe.

Actually, Stairway to Heaven is the only song I can play on guitar, but I do know other players that started just because of that song.

I think I'd say it was Blue Rodeo's "Five Days in May"... but I'm not sure, really.

I can play 'Stairway' on piano

I don't play guitar, but my husband does. He'd been wanting to learn to play for a long while, but the song that really made him want to go out and buy an instrument was Steve Vai's Bad Horsie. At that point he made himself a fret board and started practicing. And like a good wife (a very good wife. I rock.), I pawned a bunch of jewelry, including an antique diamond ring, and bought him an Ibanez for our anniversary.

I can play Stairway on the piano too.

I'm not sure there was one particular song, but the intro to "Roundabout" always made me want to be able to play it, and now I can.

idk. I dont think it was really a song in general, but I know I never would have learned if not for Elvis Presley. The first time i heard him I just had to play like him. Now i can play almost all of his songs.