Pros
Depends on what arm of NBC you work for and what location you are in - but NBC as a whole is worldly recognized - which is great to be part of a company that has that much recognition. Its also got lots of different places to move around within the organization - so you dont have to be stagnant if you are wanting to do something else or try a different division. There is a good amount of work/life balance and the compensation is very much up to par with what the salaries are in the industry.
Cons
Its a big company - a corporation that is concerned about bottom line. Although I was working with a very strong division of NBC, I never got the chance to even see what the top people are that ran the company. They did not get out and meet the people that were working hard to make the corporation money every day. I know they couldnt do that with every employee because its such a big company but there should be some reward for working so hard throughout the year to keep the corporation surviving.