Originally Posted by Muzak Geek

Don't know for sure, but I would think that the most used name has gotta be Mary…

That girl's mentioned in a LOT of songs:

Wind Cries Mary - Jimi Hendrix
Mary - Sublime
Mary, Mary - RunDMC
Hail Mary - 2Pac
Mary - Tori Amos
Mary - Scissor Sisters
Mary - Sarah McLachlan
Mary Jane's Lat Dance - Tom Petty & The Heartbreakers
Mary Jane - Pete Townshend
Mary's Place - Bruce Springsteen
Cross-eyed Mary - Jethro Tull
The Eyes of Mary - Cracker
Mary's Garden - Human Nature
Mary - Oingo Boingo
Take a Message to Mary - Everly Brothers (written by Dylan?)
Mary Lou - Bob Seger
Crazy Mary - Pearl Jam
Mary-Anne With the Shaky Hands - The Who

She's probably mentioned in even more songs than I've got listed here - But this is all that I could come up with right now.

Anyone else come up with any popular names in song titles?