Not all of these are the character's first kisses EVER, but what the heck.

The Wonder Years: Pilot (31 Jan 1988.)

(Cue "When a Man Loves a Woman)
NARRATOR: It was the first kiss for both of us. We never really talked about it afterwards. But I think about the events of that day again and again, and somehow I know that Winnie does too.

My Girl (film, 27 Nov 1991)

VADA: Close your eyes.
THOMAS: But then I won't be able to see anything.
VADA: (raises fist) Just do it.
THOMAS: OK, OK.

Boy Meets World: Cory's Alternative Friends (15 Oct 1993)

TOPANGA: It was my first one too.

Great Expectations (film, 30 Jan 1998.)

Hey Arnold!: School Play (8 March 1999)

ARNOLD: I guess we did alright, Helga.
HELGA: I guess so. Except for that disgusting kiss, yuck! I practically threw up!
ARNOLD: Then why did you kiss me so long?
HELGA: Hey, I was acting, Football Head! I was being professional! You think I wanted to do that? I practically gagged!
ARNOLD: (sighs) Whatever you say, Helga.

The Suite Life of Zack & Cody: The Fairest of Them All (18 March 2005)

CODY: So much better than a bike!

The Suite Life of Zack & Cody: Kisses and Basketball (1 Jan 2006)

CODY: We did it! We did it!
(Max kisses Zack)
CODY: I mean YOU did it...

Ned's Declas.sified School Survival Guide: Double Dating (3 June 2006)

MOZE: Suzie's on the dance floor.

Zoey 101: Chasing Zoey (2 May 2008.)

ZOEY: Can you feel this?
CHASE: Kind of.
ZOEY: How 'bout this?