For me, up until a few years ago, sunflower oil was the only oil we used. I don't know what to tell you about the brand, I know only both my mom and grandma buy Папас. 
When buying a type of food for the first time, I usually go for whichever I've heard most about from my friends or family. then I consider the price - I don't take the cheapest nor the most expensive. If the difference is not that great, I just pick one and take it, hoping for the best. Whatever it is, it's not worth it spending more than several seconds deciding.