Rib eye is what I used to cook, almost exclusively, back in Texas, over the grill with wood smoke from hickory or mesquite. I loved the tender, tender outside and the moderately tender inside, and like you say, JP, the fattier areas around the meat made it superb.
I like ojo de bife here somewhat, but it's not exactly the same cut of meat as what I was used to back in Texas, at least most of the time. When I buy it here, I believe they have cut out the bigger, not as tender portion to sell, without leaving on the fatty and very tender portion around the outside, although there are a couple of restaurants who have served it that way, I've noticed.
I buy a couple of kilos of bife de chorizo at about 25-30 pesos a kilo, then slice that whole piece of meat into 2-inch thick steaks and grill them on the parilla. The way most carniceros here cut the meat leaves a good ring of fat along one side, which does pretty good for bringing some flavor to the meat.
There are some lomos that are good, but I often find myself much more dissatisfied with lomos I have bought at the carniceria as opposed to the bife de chorizos, which are usually of a consistent quality. Nothing worse than paying for the lomo and getting a tough piece of meat.