After waiting overa year for a d800 or watever nikon wanted to call there full frame with video we bought the 5dmkII. Still reading the manual but so far were happy. Just wanted to introduce myself and say hi. Just got the 24-105 and would like to add a fixed prime and larger zoom. Any recomendations or advice. The salesman at the camera shop was a pure nikon guy and the nikon rep was there also visiting and they both did there best to push us to the nikon but in the end my wife just wouldnt settle for less then full frame.
For a prime -- it depends on what you are shooting. For a general purpose prime I'd suggest the 50mm f/1.4. For a tele zoom, Canon make 4 different 70-200mm lenses, all of which are highly regarded.
If you want a longer lens than that -- a portrait prime, I'd suggest an 85mm lens. There are four -- Canon 85mm f/1.8 and f/1.2, Sigma 85mm f/1.4 and Zeiss 85mm f/1.4. All of them are worth considering. Zeiss lenses are manual focus only.
If you want a wider lens, Canon make the 35mm f/2 (dated design but good and inexpensive) and the 35mm f/1.4. Zeiss make lenses at this focal length, I don't know what they're like. I don't recommend Canon's 28mm f/1.8.