Hair straightening Irons

I have naturally very wavy hair that I like to blow straight on occassion, however when I blow it straight, It isn't 100% straight.

I go for blowouts and they use an iron on my hair after they blow it out. I love the way it comes out.
but when I can't get there, I do it myself
Should I buy my own and if so, can someone recommend a good one?

Thanks