Gotta be his version of All Along The Watchtower. He just takes those lyrics and adds that nice choppy sound and makes it twice as brilliant. So much so that Dylan now does Jimi's version of the song when he does it in concert.
My very favorite Hendrix moment is in his performance of Wild Thing at Monterey Pop, in the middle section, when he's jamming, at one point you can clearly hear him playing about two lines of Strangers In The Night. Cracks me up every time.
HAPPY BIRTHDAY JIMI!