Haas are
the best. Wish I could get them more often ...
Avocados in general are way up high on "Ayrton's list of fattening foods she can't resist". I know what you mean about the spots and streaks inside -- always very disappointing, especially if you've paid a princely sum for them.
No, I haven't found a way to predict an "off" interior either. I know to buy them (if I want to eat right away) when they "give" slightly under finger pressure, but sometimes that yields a flawless light green interior and sometimes it yields a green and brown/black interior with stringy bits
. Personally, I throw out any part that isn't a nice, smooth, even green.
Clive, I think you're describing local varieties since I've never seen anything even close to yellow here (which would mean sourced from Africa, Crete, or Israel) or in California where they're native. Do take photos -- getting them to post isn't hard (shout if you need help).
Ways to eat them? Okay, my favorites:
-- in an omelette, preferably cheese, sauteed onion, mushroom, and avocado
-- in a burrito, especially with grilled chicken
-- in a cheese sandwich: good sharp cheddar, mayo, avocado, pepper
-- in green salads
-- smushed on Stoned Wheat Thins with salt and coarsly-ground pepper
-- in my VERY favorite sandwich: chicken salad with cumin on soft dill rye!