I actually like all the lines mentioned above, except the Bobby one (and the bowl of Trix doesn't help -- I was totally baffled by that interaction for a long time) and the coffee one, which doesn't quite make sense to me either. Why would Ennis say "he's from Texas" in response to an offer of coffee?
But OK then. Speaking of hardhats. Let me preface by saying that I totally subscribe to the Heath-is-God viewpoint, his performance is exquisite, I'd put it against anything done by Sean Penn or Brando or anyone else in the history of movies, he has gone from being an actor I hardly noticed to being my favorite actor, he definitely should have won BA as I've argued many many times ...
But. There are two deliveries of his that I don't like.
I don't like when he says he's dropping the girls off at the grocery store and suddenly briefly sounds Australian. That makes me cringe. I'm not blaming him so much, because I'm sure it's hard to maintain a foreign accent while doing everything else (as Heath has implied in interviews). But with all the care that's taken to every other detail, I don't see why they didn't just redo that scene or the sound or whatever. (Actually that whole scene seems a little bit "off" to me, perhaps because as was discussed elsewhere it was originally supposed to go in a different part of the movie.)
And the other is in the otherwise phenomenal "can't quit you" scene. He obviously is great in every other way in that scene. But I don't like the way he says "if I should come to know them" because he says "them" rather than "'em," which I think Ennis would actually say.
Come to think of it, I'm not crazy about that whole line. I love Ennis getting jealous and angry about Jack's trips to Mexico. But threatening murder seems a bit much, even if we know he wouldn't actually carry it out.