@rileycran
It’s a tough one.
Lots of it is totally unnecessary to long-term continuity (which is self-contradictory anyway). Lots of it sucks. Some of it sucks but serves longer plot arcs. Some of the best almost works with no prior knowledge.
So… ¯\_(ツ)_/¯
I’d say start somewhere in the modern series, whose modern pacing will feel more familiar — maybe from the beginning, but maybe skipping some duds. Then maybe sample some classics for the contrast (I love “City of Death”).