No, even the very long video cards can fit in a mid tower (some with a little mod to the HDD bays, but most without).
I use full towers for NAS machines that have 9-16 HDDs, otherwise most of my builds are mid-tower or smaller.
Clients really like smaller builds now with mATX boards. One of my favorite small cases is the Silverstone PS07
HERE that will hold a big video card (only one though) and cools well and you can pack enough drives in, although it takes planning, cable management, and the first one I built was a biotch. After the first ten it was so easy and such a sweet little case.