What are some products that can help me with straightening my very curly hair?

I have super natural curly hair. It's really fun and I love it, but I don't like it to always be curly. Every time I straighten it, I just get a big mess with frizz. I love volume, but it's not a good type of volume! I do use some spray for the straightening and stuff, but it's always so wavy and frizzy after I straighten it. I want a lot of peoples' opinions. What products could help me with my problem?