My one suggestion would be to read elantris & warbreaker before era 2. Era 2 have a bit more cosmere content that can cause some head scratching.

Yeah, I think the action and magic systems allow me to overlook weaknesses in other places. What might be fine for some isn't for another. But I 100% suggest mistborn era 1 to get a general feel for Sanderson.

It's definitely the one that's been on my shelf the longest. But thats a hell of an endorsement!

Its a tie between Mistborn & The tombs of Atuan.
Mistborn for the great action.
Atuan for the beauty of prose.