I'm looking to invest into a good quality hair straightener, which would be the best one?

I have fine, wavy, long, dark brown hair (that is sometimes frizzy.) I'm looking for the hair straightener that will straighten my hair that will straighten my hair with the LEAST amount of damage. I heard the Chi is good, but I also hear that there is a new product just introduced to the market that is better. The Sedu hair straightener has also caught my eye but I'm not sure its for me or not. So what is better, the Chi, Sedu, or another product all together? I also use Thermo shine by keratin complex before I straighten my hair.