Delightful! This might have been the best interview process I have been through.
Professional and friendly: Very friendly environment, very smooth communication, challenging and interesting interview questions, great interviewers.
The follow-ups between the interviews were very timely, personal and amicable, which made feel like a "guest of honor" in the process.
Personal touch: This is the first company for me which did not try to "give me the job", but rather identified how I may contribute best - to myself and for the company, called me for a discussion, and suggested a slight (and quite appropriate for me!) adjustment to the role I was seeking.