I have right side of the plane OCD. I have been to BA over 40 times. I fly down this weekend in 2A on an AA777. Left side.
I did it on purpose to see what there is to see.
On the right side you don't have as much glare from the sun, but people trying to sleep around you will not like you very much if you open the shade. I usually don't open the shade until they start doing breakfast wake ups 45 mins out. Like a previous poster mentioned lots of pampas, you can pick out a few small towns. When you get closer to EZE you can see the villas.
I fly down at night on AA in J or F.
Flying out of AEP has much better scenery.
When you fly MIA to EZE you fly right over Cuba at night and can see the island lights.