A great environment of immensely talented people who are eager to both learn and teach. Company's average age of 37 leads to a diverse community. Good mix of gender as well. Company size allows you to "know" everyone yet have a large community of coworkers. Good salary (for me anyway). Good benefits, such as social events and a yearly out-of-country trip. Great office (shared with Crayon) with awesome cantine. Top-tier hardware, which is highly appreciated as a developer. Exciting projects.
Contras
Being a smaller company can lead to longer "bench time", but simultaneously more exciting projects.