[don-o]

I see no need at all for olive oil. My ancestors did just fine with lard (hog fat)

[Beagle8U]

Its just my opinion, but, I'd save the lard for pie crusts (the best you can get), I've always been told that any animal fat can become rancid over time and is a poor choice for seasoning pans that will retain the oil for long periods of time.

I guess its a personal choice.

I would say that peanut oil would be ideal because it can take higher temps than most cooking oils without burning, but some people can have a severe reaction to peanuts and cast iron, being porous will retain the oil for a long time.