It's best if the title you present to the world reflects what you actually DO. If it's just you, "Owner" is best. If you have two employees -- say, a book keeper and a web designer -- figure out what you "do" and that is your title. If you're an engineer, "Owner and Engineer" might be the way to go.
You're not going to fool anyone with just the title "CEO". They are going to ask you pointy-headed questions and you're going to get nowhere with that. In particular, if you claim to be the "CEO", you might get asked business executive questions you just can't answer. You'd have been better off with "Engineer" in your title -- at least you could answer those questions.