Ok, good question!
I would recommend this list for someone shooting video on the Canon 7D or 5DmkII. I know one camera is full frame and the other is crop, but you can figure out the difference.
Wide Angle: Tokina 11-16mm f/2.8
I use this lens on the 7D and it is awesome! Great for follow cams and some interview stuff as well. Mostly for 7D, you can find a similar one for the 5D.
Nifty Fifty: Canon 50mm f/1.8
I use this as my primary interview lens, for around $100 you cannot go wrong! A step up is the 50mm f/1.4, but for how much more it costs, the image is not even that much better so I don't think it is worth it. This is good on both the 7D and 5D.
My "Kit" Lens: Canon 24-70mm f/2.8
This lens is legit! If you have the choice between buying a camera body with a kit lens, or just the body. I would recommend buy just the body and shell out some extra money for this lens. I have used this lens so many times and it is awesome! It will hold its value very well and exceed expectations every time. This is good on both the 7D and the 5D.
Long Lens: Canon 70-200mm f/2.8 IS (version 1)
This is my long lens that I will use in the backcountry mainly, but sometimes other things are appropriate as well. The IS in this lens is key, I could have bought the f/4, but I felt that for resale value as well as if I ever wanted to shoot something in low light that it would be worth it. This is good on both the 7D and the 5D.
Doubler: Canon 2x Teleconverter
This is the doubler that I use with the 70-200mm above. Turns the lens into a 140-400mm f/5.6. Usually when I shoot in the backcountry it is a bright sunny day, so I am not worried about the lens being f/5.6 instead of f/2.8. This works with both the 7D and the 5D.
These are all lenses that I currently own and use day to day while I film. I really would like to have some more money to get some more primes or some other cool lenses like a tilt-shift, but that will come with time.
If I missed anything, or someone has any questions, please do not hesitate to ask!