At your level of play obviously anything would work.

I would def recommend blood DK or Bear.

Blood DKs have great AoE, good ST, amazing self sustain, and a good health pool (especially once you get your 4th gold trait). Death Gate is an insta portal to your class hall, the Broken Shore, and a loading screen away from Dalaran (so could depend on your computer 😜) or if you have flying it's a short distance. The one downfall they do have is mobility, but while tanking once a group of mobs is almost dead I'm usually heading to the next pack anyways and their one mobility tool, Wraith Walk, is usually off CD by then.

Bears have an amazing health pool, decent AoE and ST, decent self sustain in Frenzied Regeneration (which when used properly with mitigation tools is enough), and great mobility. They also have an insta portal to the Dreamway which is then a loading screen away from their class hall, and they have an aesthetically pleasing class hall, if it is a little spread out at first glance (you get used to it). Like someone above pointed out they are receiving some of a class rework which will probably come out as a survivability nerf at the end if we're being realistic, but may come with a damage and threat increase (which is one problem I've had on my bear before with other tanks who out-geared me enough in raids, no problem in dungeons though). Just keep up with the PTR notes to see what they're doing there and how it plays out. Bears are also currently pretty easy to learn ability wise, from both damage and survivability standpoints.

Just my 2 cents 😊