Multiple Interviews - Recruiter, then HR & Hiring Manager, then upper execs, then CEO. In my career have never been called back for more than two interviews before being offered the job, so in my opinion, companies that make you come in multiple times are not clear on what they want, or are being nitpicky and judgmental.
If you have the skillset, then it really shouldn't take 3 or 4 interviews to make a decision. Personality can be determined in those first couple of interviews.