There is an interesting assortment of recommendations here, from various Wagner scholars, performers, directors, enthusiasts, etc. (including yours truly). The many contributors include Barry Millington, Hans Jürgen Syberberg, and Dame Anne Evans.
I am sure that no one will agree with any particular set of recommendations - I should be astonished if anyone agreed with mine - but a merit of such surveys is to inform or to remind one of other possibilities.
The rest of this excellent site is well worth exploring.