I've always found primes to be my favorite types of video lenses because it forces me to move around my subject and my scene, rather than using a zoom to recompose and reframe. That being said, I think my all-time favorite video lens is the 24-105G, simply because it's like a jack of all trades. While it's not the fastest, it IS super sharp and the color/image quality looks divine. I'm also partial to the new 50mm 1.2GM because WOW, it makes everything look so good!
What about you? What are your favorite lenses to use for video?
Even though I'm on primes most of the time, I have to kind of agree. If I was only allowed to have one lens to cover everything I have to shoot in the course of a year it would be the 24-105 f4. It's so versatile... has very close focus for a zoom, and I find myself using the 85-100mm focal lengths all the time. Amazing lens and an unsung hero in many ways.