"Untouchable Face" by Ani DiFranco is a good one about jealousy...
Think I'm going for a walk now... I feel a little unsteady
Don't want nobody to follow me 'cept maybe you
I could make you happy, you know, if you weren't already
I could do a lot of things... and I do
Tell you the truth I prefer the worst of you
Too bad you had to have a better half
She's not really my type, but I think you two are forever
And I hate to say it, but you're perfect together
So fuck you and your untouchable face
And fuck you for existing in the first place
And who am I that I should be vying for your touch
And who am I... bet you can't even tell me that much...