The first time I saw it, I got misty for the first time at the phone call to Lureen, then teary when Ennis first entered Jack's room, and it was so stark, and I thought, "How could *he* have lived in that room?"
The second time I saw it, I began weeping soundlessly at the beginning of the lake trip, knowing it would be their last time together, and never let up until the credits finished rolling.
Since then, sometimes I'm gripped by it again and start weeping at any number of places, as early as the second tent scene, and as late as Ennis' last line. Other times, I've been able to watch it all the way through and not shed a tear. No matter what, though, I never get over that shot of Jack's face after he's been hit with the tire iron. It makes me gasp out loud and put my hand to my mouth every single time.