
Good atmosphere, good coworkers, and good clients = happiness.
In my immediate team, there is no drama (not always the case). We have a good system set in place, and we thrive on getting the work done.
Everyone seems to get what we're trying to do. In my immediate circle, there isn't drama (which hasn't always been the same in other teams), so that's GRRRRREAT!
Cash-money! Perks are great too (i.e. food, Christmas gifts, etc.) - no doubt, but I believe the vast majority of the company's employees prefer an increase in their Christmas bonuses or their overall salary as the best perk.
Continual source of communication and understanding as far as a career path goes. In my experience, they are great with working with me on my goals, as well as assist in various client issues and work. A+ people!