I've worked at a few other (pretty great) workplaces in my career, but I can honestly say that AppNexus has done by far the best job building and maintaining a positive, productive and nurturing company culture. Everything ties back to the company's incredible values and mission, which help to keep things in perspective and ensure everyone is "rowing in the same direction", so to speak. This is the first place I've worked where I feel I can truly be myself (as opposed to trying to conform to a certain office culture), and succeed professionally while doing so. As a result of the above, I've been here for over 3 years - and I plan to continue to work here for years to come!
WFH always an option; Individuality supported (and encouraged); Perks like free Lunch on Fridays, free in-office meditation & exercise classes... I could go on and on!