Enchanter or tank support?

Personally, I much prefer enchanter supports just because it's my play style.

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Which ones are more meta right now? Which do you prefer?

It really depends on the lane you're facing. Some enchanters really play well into melees, and if the other team picks an enchanter, you generally don't want to put yourself at a range disadvantage unless you're playing for late.

You can play a melee into a melee (like, say, Tahm into Braum or something like that), but it's really up to your particular playstyle and champion preferences.