I have used GIT and PERFORCE. GIT will only git you so far (ba dum dum). Perforce UE4 support is much better and an Epic developer told me that is what they use to manage Fortnight. There is a free version for small teams. However, Perforce is not simple to manage. If you move or rename directories in the project it will corrupt the server branch. The merge is not as user friendly as git. Binary merges are not possible for obvious reasons. When integrating with Visual Studio you need to set several files to ignore. There are technical articles on how to do this. If you don’t your project will be corrupted on the next sync. You will find that you are frequently re-creating your base repo because of sync issues with other members.
So, for just yourself, I recommend making a zip file periodically.
If you have less than 5 people and not a huge project, use Git.
Five or more people and/or lots of large assets, use Perforce, but be prepared to spend alot of time managing the repo.
Lack of proper enterprise grade source control in Unreal is, in my opinion, one of the largest weaknesses of the toolchain.