nprofile1qy2hwumn8ghj7un9d3shjtnyd968gmewwp6kyqpqsrtfsw6mua8nmjumlyq4murjjxj6k58ylkdpqf28dr7p3646tyfsl26806 (nprofile…6806) nprofile1qy2hwumn8ghj7un9d3shjtnyd968gmewwp6kyqpqrv4738d6q3nxf24v4gmg4u7lh3udmarsttfzp7q0xttdlqk5ls3ssayzy8 (nprofile…yzy8) Perforce (aka "P4"). IIRC it's free for <10 users.
I have also heard good things about Subversion ("SVN"), though never used it myself.
GitHub is also pretty decent! Not sure how well it scales to big teams, but I like it for small projects that you don't mind being somewhat public. Better than nothing (or git).
I am also watching Ark VCS - it's new, and it is making all the right noises (it's very P4-like at heart), so I'll be excited to see how it develops.