I can't seem to remember a very funny commercial I saw on TV. Here's
how it
goes...
A family is eating breakfast at the table when a picture of a cartoon
sun suddenly comes alive and comes out of the cover of either a box of
juice or a cereal box. The cute little sun notices that he's not being
accepted as a sun that continues to say "don't you like me? I'm full
of
vitamins and nutrients," while the whole family panics and runs away.
At
the end of the commercial, the sun chases the family into the living
room and the mother falls on the floor dramatically reaching for her
daughter as if the sun were to take her away. Then, the ad is shown.
I've been looking everywhere for the company's name, the title of the
commercial, or even a clip of it. Please help me find it!

The fictitious product was "Sun Fizz", and it appeared in a 1998
Sprite commercial directed by Spike Jonze.

I found some still shots of the sun character here:
http://www.migoto.com/western/HTML/work/cgi_sprite.html

Two leads I found in trying to track down a downloadable version of
the commercial:
1) A multimedia archive that hasn't been updated in more than 2 years.
A zip file is shown in the list, but is not downloadable. The page
author's email is given at the top of the page, so it might be
possible to contact him directly.:
http://www.sightspecific.com/~mosh/Videos/vidlist.html

2) An unconfirmed link to the video on Ad Critic (subscription
required). I couldn't get to the page because I am not subscribed.:
http://www.adcritic.com/content/sprite-sun-fizz.html


Search strategy:
"I'm full of vitamins" 
lead to "Sun Fiz" as the name, which was shown to be a mispelling on
further searches.
"sun fizz" commercial
produces numerous hits, confirming the real spelling and providing
further leads.

Cheers,
nauster-ga

Lighting speed answer! Very helpful an concise. Brought back memories! Thanks!

Got a link to where you can download it. :) 
<a href="http://sickjokes.about.com/library/blmedia_sunfizz.htm"> Clicky </a>

Curses....no html tags. Oh well.