Pros
Unity is the best place I've ever worked. We have a clear goal to make creative tools available for free to the most people possible - which as a creative person is super compelling. I've been at Unity since 2011, and I freelanced for them before that. Having had the chance to watch the company grow from 100 people to 2000 at the time of writing and work with an incredibly diverse mix of people on all kinds of projects has made my time here so far unforgettable. Pros are challenging technical and design problems to dig into, travel, interesting mix of people and a culture of management that genuinely cares about it's employees.
Cons
Unity is very distributed but that's the only con i'd suggest as for some people working across many offices, this is challenging.