If you are asking about the best hair straightener brand then I would recommend Philips HP8316 / 00 as it is made with ionic and keratin coating technology that will give your hair straight and beautiful hair in the shortest time. This straightener from Philips is designed to have long and thick hair with minimal damage.
Philips is a decent brand, for sure. And this particular model is indeed worth trying. Though nowadays most brands have straighteners with ionic and keratin coating features.
After various tests, I would recommend trying out these models like GHD Platinum, Babyliss Pro Nano Titanium (they also make decent hairdryers), Kipozi Professional Titanium and Remington S7310. That's not a complete list and there are more decent straighteners that were mentioned in the review on my blog
a while ago about this topic.