Another minority opinion: I sleep best in a bulkhead B/E Diamond (ex-CO BF) seat... Service is probably a bit better on average on LH, but the food can be quite bad, too. I take whichever is more convenient at the time.
Of the *A carriers, I actually like flying AC TATL these days, if I have time for the connection. Everything is pretty good - service, seats, IFE, food/drink. Transit logistics at YYZ/YUL isn't ideal, but it's not the worst thing in the world. The Acqua di Parma amenity kits are super cool, too.