As long as its cold pressed extra virgin, then it's all down to taste - your taste. Some people find the paler oils have a lighter taste for using on salads.
I prefer Greek - Kalamata, the best olive-growing area in Sparta.
Some people like Italian.Others like Spanish. They really do have different flavours.
Maybe just go for the cheapest in the cold pressed EV category. Like all things, there's a bit of snobbery about the sources :wink:
I used to use rapeseed oil on "Buy British" grounds. I can't remember why I stopped, but I know I had a very good reason. :think:
Viv 8)