I agree, both companies produce great cards, but for slightly differently crowds IMO. nVidia seems to be slowly moving its R&D more towards the professional crowd, while ATI is quickly filling the void left by nVidia in the enthusiast and gaming markets, especially since we are currently awaiting the NV35.
Text? Video?
Ah, two very important tasks as well, so to add further confusion, I would not install either an ATI or nVidia card for video work. I use Matrox Millennium series cards for A/V purposes. Can't beat the 2D quality and performance.