For the first song, how about Girlfriend by Avril Lavigne?

What about Teardrops on my Guitar by Taylor Swift?

Paramore's 'Misery Business' may have some relevance in your 1st category.
And also, good suggestion Dr. House.

Mr. Brightside by the killers(other way around though)

Last Kiss by Pearl Jam

Stan by EminEm(rap though)

Almost any Beatles song!

For your first song : John Lennon - Jealous guy !! I love so much this guy !

Well, and for the second one, check this one : Aqueduct - The suggestion box (Aqueduct - The Suggestion Box - I Sold Gold | Deezer)

For the first option, no self-respecting rock n' roll band would write a song about this.

For the second one, I'd choose Maneater by Nelly Furtado, no just kidding.

Um, Got You By the Balls-AC/DC?
Not exactly the best choice for class though lol.

For your first one:
Found Out About You - Gin Blossoms (male PoV)

Second:
Living On A Prayer - Bon Jovi.
Don't Stop Believing - Journey

And I really, really hae to throw this out, but it kinda works:
Sk8ter Boi - Avril Lavigne

1st Category: (Sorry, I guess I can only suggest some stupid teen-pop songs for this one...)
What You Do About Me - M2M
Jennifer - M2M
Another Day - Lene Marlin
Number One - Skye Sweetnam

2nd Category: (I'm not really sure what you mean, so these might not be the best suggestions...)
You're Still The One - Shania Twain
I'll Stand By You - The Pretenders
Iris - Goo Goo Dolls
Wherever You Will Go - The Calling
Trainwreck - Demi Lovato

true love?
I don't wanna miss a thing - Aerosmith or David Cook.
emm.. maybe I'll be - Avril Lavigne?

Girl wanting a guy: Alone by Warmen.
Not very mainstream or anything, but the closest I could get.