What are the best brands of hair straighteners/flat irons?

i am looking to buy a new flat iron. I am wondering what the best brands are. Not too expensive like I cant afford a chi. I have wavy frizzy hair and I have a conair straightener now and my hair stays straight for like 2 hours then starts to wave. I am looking for one that will keep my hair straight all day, and leave it silky and smooth and not damage it, cuz my hair is naturally VERY healthy and I don't wanna dry it out. Thanks!