I enjoyed 1.6 through 2.2 the most. In particular, I really enjoyed 2.1 (IC) and 2.2 (Orsinium). Combat was fast and fluid. It wasn't perfect as ball groups were very strong via barrier/purge/rapids, but all other combat was much more interesting than it is today. IMO, 2.3 is when ZOS began its 'raise the floor, lower the ceiling' effort and that has slowly ruined PVP combat for me.
The return of permablocking in 2.4 and proc sets took a lot of fun out of combat. As sets were updated to VR16, the game became less balanced. This was especially true in 2.6 (1T) when soooo many sets were introduced. The more sets that are available, the more difficult it is to achieve balance.
I enjoy objective conflicts the most, but the otick buff has ruined them for me. Keeps are often not defended and flagged keeps attract offensive faction stacks as players race for a guaranteed minimum otick of 6k.
Worst of all, I feel the culture is changing. I feel Cyrodiill is full of players straight out of Alik'r (dolmens) who enjoy zerging nearly undefended keeps with 60 other players.
ESO PVP -- AvA in particular -- seems like a rudderless ship without direction. There is no visible leadership, no apparent vision, and adjustments/bug fixes come far too slow.