I agree with andesmandes that Cardenal Samoré is nice, easy do drive and good views. But, everywhere in the Andes has a good view. I recommend taking a day pass at the all inclusive hotel on the Chilean side, bswimming and eating buffe lunch until you think you are going to burst, but will just have one more desert anyway. If y are staying the night, stay at the cabañas further up the road instead.
This border crossing can be tedious though, depending on when you go. In high season it can take up to five hours to cross, three hours waiting on the Argentinian side, an hour driving between checkpoints (with viewing stops) and another hour at the Chilean side. There is talk that it is to be simplified, but I don't know when or how or for who.