Yeah you might want to put a spoiler heading on this...even though my friend and I got the movie ruined for us when someone spray painted what happens at the end on a bus stop sign. That was weird, to say the least.
But I still saw Marley and me. And actually it was very good, despite knowing what happened. I don't want to be a pain in the butt or even defending the OP because of this spoiler, but I would still see the movie because of the good parts, not because of the end which really has nothing to do with the plot or what's going on at all. It's not like the sixth sense where if someone spoiled that for me I'd have to punch them in the face. Because it honestly doesn't kill the ENTIRE movie.
With that said, I'm just giving my two cents. Not trying to be a jerk or change anyone's minds.