Even though I'm a teenager myself, I don't know alot of teenagers. I guess I'm just not very social.
Here are the names of teens that I either know or have met, since there aren't many:
Katelyn (Ugh. Can't they just use the original Caitlin?)
Ashley (And Ashlee)
Hmm, I don't know that many teenagers anymore. I'll just list some - some of these names are more unusual than common for that generation.
(2x) Christopher "Chris" - 19
(2x) Matthew "Matt" - 19
Nicole (a few, various ages)
Cassandra "Cassie" (19)
Ann "Annie" (14)
Darianna (not sure age, maybe 14-16)
Here's my theatre troupe. Everyone is roughly 12-19, with a few young twenties in the mix:
Caroline (two, I'm one of them)
Andrew (four of them! But one goes by Drew)
Alex (not Alexander, but I forget the legal...)
So, lots of classics for the guys, and several trendy 90's for the girls.
Edit: This is fun! Here are a few more lists:
From my church group (all girls aged 13-14)
Lea (full name Illiana*)
Lauryn McKenzie (usually just goes by her middle)
Cassandra (nickname Casey)
*I love her siblings names, too. Her family has four kids named Audriana Aurora, Kathryne Isabella, Alexander Xavier, and Illiana Ariel.