Pros
Leading edge technology. Lots of very smart engineers, no office politics to speak of. Good salary compensation. Gave out good stock options in the past. Flexible work hours, feel free to work as much as you can.
Cons
nVidia excels at hiring the best and brightest engineers, put them in mind-numbing, dull, repetitive jobs. You'll become obsolete in the job market after a few years at nvidia because you get too used to all the internal tools that you forget how to use industry standard tools. Some bright engineers get promoted to become not so good managers, and ultimately lousy middle management. Very little interaction with co-workers outside of work, everyone works long hours, then hurries home, just to come back eight hours later to repeat the cycle. Coworkers who quit, get laid off, or fired, simply disappear with as little fanfare as with the new employees who come in to take their places.