I'm not sure I'd say it has "won" - such a phrase implies a long-term positioning at the front of the pack, and those that came before it for code hosting (SourceForge, Google Code) enjoyed their time in the spotlight before having something new come along.
BitBucket in particular have made a good attempt after the Atlassian takeover, with the infinite free private repos being the most interesting part - I use it a lot, but mostly because I do a lot of small personal projects, and so the "social" features of GitHub - those which benefit most from its prominence - are mostly meaningless to me.
BitBucket in particular have made a good attempt after the Atlassian takeover, with the infinite free private repos being the most interesting part - I use it a lot, but mostly because I do a lot of small personal projects, and so the "social" features of GitHub - those which benefit most from its prominence - are mostly meaningless to me.