Which heroes are currently considered 'main tanks'?

Hi! Recently I started getting back into HotS after a long hiatus and was wondering which warriors can currently be played as main tanks/solo tanks. For example, back when I was playing, Arthas was considered a bruiser, but I think he can also be played as a solo tank now?

These are the main tanks I can think of right now: Muradin, Diablo, Johanna, Garrosh, ETC, (Taunt Varian maybe?)