GitHub

Pros

Very easy to host a repository and to fork other repositories. It is easy to search other repositories.

Cons

None that I found. My only request would be to be easier to download single files without having to view the file first. If there were checkboxes and a download option that would be great.

Pros

- high availability
- built-in code review, wiki, issue tracker, artifact hosting (private beta)
- great third-party tool integration
- automate everything
- uses git
- developer friendly company
- free for open source projects
- mature

Cons

- issue tracker could be more sophisticated
- new features could be developed more rapidly (although this has improved recently)
- native apps are not up-to-par with competitors, but luckily there are many free alternatives
- was bought by Microsoft, I personally would have liked to see them stay independent

Pros

Usage is well documented like cloning repository using ssh, create a branch, create a repository, etc. Reviewing PR interface is great. You've option to mark the files you've reviewed which is really helpful for gigantic pull requests. Easy integration with IDE like Intellij/Eclipse and you can push your changes directly from the IDEs.
Features like squash/merge from UI are really great and saves a lot of time. Jira integration of pull requests is awesome.

Cons

Very limited private repositories for free users, it should give an option like this number of lines of code for the private repository as a limit rather than not providing or limited private repositories.
It sometime might get complicated for new users while working on same codebase at the same time like stuck between merge conflicts, rebase issues etc.

Pros

The best part of this software, in my opinion, has to be the repository insights that comes with the pro version and above. These insights have proven to be extremely valuable when managing larger-scale projects with multiple developers working on the projects. Not only is our project management team able to get live updates on the progress of the project with each commit, but our team is also able to hold each other accountable by seeing their progress via the progress tracking feature and individual commits. Another notable mention for Github is their desktop GUI. This is such an incredibly easy tool to use and it makes the entire GIT experience much easier to understand and maneuver.

Cons

The one issue i had with this software is the repo search functionality. This part of the software can be confusing to learn to be effective with and it takes some time to be proficient with, which can be a hassle for some of our newer members of our project management team.

Pros

Very sofisticated, today it gives us more freedom and we are able to use private repositories.
Github is the reference of version controls, and we are using it every day ( in our organization, and as well with a couple of open source products ).

Cons

Sometimes it's confusing, I love the simplicity of Gitlab, but it's not really a full comparison, both softwares have their own pros and cons. But i find that Github is sometimes confusing, and the options and how to do simple things are hidden.