I like Google Code a lot -- if you are willing to make your project open-source, it's pretty awesome. It provides you with hosting for code (SVN or Mercurial), files for releases, a simple-but-effective wiki, and a straight-forward bug tracker. The downsides are that access control for the wiki is limited, and edits to the wiki cause commits to your repository.
I've heard good things about github, and from what I've seen of it while grabbing people's code from it, I like it. But I have never used it for more than that, because I don't have a compelling need (or desire) to use distributed version control.
In the realm of less-general tools, Perforce is a powerful version control system that is used by just about every professional game development studio I have worked at or know of. They have free limited-user licenses. You need to host and administer the server yourself, though, which is something I have very limited experience doing so I can't comment much to that.
I have used Trac for bug tracking before (and still do for my own projects that I host on my private SVN). It's also simple -- I am a fan of simple bug tracking and such, instead of systems like Bugzilla, which I think are too much trouble to configure. I don't use Trac's built-in wiki, really, preferring DokuWiki instead. There is also the ever-popular MediaWiki, if that's your thing.
Backup-wise, I mostly use Backblaze, which is awesome but violates your "free" constraint. If I couldn't use Backblaze I'd just back everything up via a cron job or something to an external hard drive and mirror that to my web server, probably.