Love At First Sight/Live-Action TV

Dharma and Greg meet and get married in the pilot episode. They first saw each other on a subway train when they were children. About twenty years go by, and they see each other again on the same train and get married later that day. The show is very heavy on the Idealism side of the scale.
- Though to be fair, their relationship does have issues. (Heck, they start fighting less than a day into their marriage!)
- And they did a cameo as the same characters on Two and A Half Men - still together but he wants to kill himself because he can't stand her anymore.
Battlestar Galactica: Lee Adama and Kara Thrace. Which is trickier than it seems when you consider the fact that she's his younger brother's girlfriend at the time.
Home Improvement: Tim and Jill Taylor.

Tim: The first time I looked at you I knew I wanted to spend the rest of my life with you.

Skins has to be the most cynical show to end this trope with a Happily Ever After, what with The Reveal in the S4 finale. (Very obviously a Crowning Moment of Heartwarming, only magnified by the rest of the speech...)

Naomi: I loved you from the first time I saw you. I think I was twelve.

iCarly: Carly confirmed during "iSaved Your Life" that Freddie had been in love with Carly since he first met her.
Lancelot for Guinevere in Merlin. She measures him for a suit of armour and it's clear that he's completely smitten. When they meet again in a life-or-death situation in season 2, he's more than willing to die for her.
The robothead 790 was subjected to the Love-Slave mind treatment in LEXX, and the first person it laid eyes on was none other than Zev whom he immediately fell in love with. Later in Season 3, 790 had an accident, and it immediately fell in love with Kai who subsequently fixed it.
There are indications of this with Grissom and Sara on CSI from the stories told about their college lecture meeting, although relationship did not ensure for years afterward.
Glee: Although Blaine doesn't clue into it for months, the looks on his and Kurt's faces during "Teenage Dream" proclaim louder than any words what exactly happened between the two of them as soon as they laid eyes on each other.