Paddlestar Galactia - "Mother-Frakin' Pylons!"
Brokeback Galactica - Brokeback music & theme with Galactica quotes
All of this has happened before... - everything old is new again, sort of
You Might Be a Cylon! - game show sendup
And some great music videos:
Meatloaf's "I Would Do Anything For Love" - Kara/Lee
Smashmouth's "I'm a Believer" - multiple couples
Bette Midler's "The Rose" - more multi-couple stuff
"Bang Bang (My Baby Shot Me Down)" remix - Helo/Sharon
Doris Day's "Teacher's Pet" - sucking up to Roslind
Green Day's "Boulevard" - Season 2 clips
"Kryptonite" by 3 Doors Down - isn't there one of this song for every sci-fi show?
One from the "Downloaded" episode, not sure what tune they use
Friends theme music video - Lee/Kara again
"Faith of the Heart" from Star Trek: Enterprise - BSG's crises of Faith
And the best of the lot, "Dear Mr. President" (by Pink, mostly Gaius) and "Ghosts of You" (everybody's lost someone).
And every once in awhile at the You Tube flea market, you stumble into something so hilarious you just have to get it even though it has absolutely nothing to do with whatever it was you were looking for in the first place - like this Stephen Colbert clip on a Ten Commandments monument from his Daily Show days.