googlecode has worked well for me in real-world open source projects -- I particularly appreciate the simplicity of the tracker and review/commenting system, as well as the ability to use either svn or hg. It does currently lack the ability to publish normal HTML online doc pages though (wikis are fine, and so are downloadable docs, but, being greedy for ever more features like everybody, I'd like to have the online HTML doc option as well!-)
In the past there were fewer options and I used sourceforge, but never really happily -- I was so glad when I could just leave it behind! I hear they have revamped everything recently so maybe it's usable now, but I don't know first-hand.
Also worth looking at is bitbucket, offering hg hosting that's free for open source projects but (differently from google code hosting and sourceforge) you can also choose to purchase the service for closed-source projects (could be handy if you find yourself doing geographically distributed development of closed-source code). There are several other sites with a similar business model but I've found the level of service, competence, and functionality, excellent on bitbucket (plus, I do like hg;-). I haven't used them in a while now because they don't (didn't?) have a code review feature like google code hosting (while the latter added hg as an option...), and I don't actually do closed source projects that could benefit from that part of their offering.