It would depend on your goals... If you just want to fit with everybody else, use github. If you don't mind the dual licensing model of gitlab, go with it. If you really care about open source, either use notabug[1], savannah[2], or self host your own. Personally, my preference is with notabug. I only use github extremely rarely.

[1] https://notabug.org [2] https://savannah.nongnu.org