I used to use just a good olive oil but have switched to a combo oil with olive oil/sunflower mix.
This has a higher "smoking" temp than Olive oil but is still good for you.
I also use the Ghee, which I didn't know was the Indian name for clarified butter until I Googled it :-[
Clarified butter doesn't need refrigeration at all and adds great flavor as well as the ability to cook at a higher heat without smoking and burning.
EASY to make and worth a look if you like butter in your dishes ;)