Atlassian Stash provides self-hosted git repository management that provides code review, and is getting better with every release. It is based on the concept of pull requests also but provides workflow better suited to teams, including the ability to require successful builds and reviewer approvals. In addition it has awesome diff views and a plugin architecture for customising behaviour and integrating with other development tooling.

https://www.atlassian.com/software/stash

Disclosure: I work for Atlassian