What is the best form of employment (at a startup)?

Currently, I am a contractor working in the EU. I normally send my clients a VAT tax invoice every month, which has been great for optimizing the amount of taxes I owe. I pay VAT (23%) + income tax (5%), compare that to 31% and 40% (tax brackets) I would pay as a regular employee. I can further reduce the amount of taxes owed by subtracting expenses, e.g. buying a laptop.

For those of you that have worked at a startup (or otherwise) in the U.S., what is the best form of employment in terms of maximizing the amount of money you take home? I want equity in the startup I am applying for. It seems that most people working at startups are regular employees but is that really the best thing to do? I’m curious on your thoughts and experiences on this matter since I haven’t been able to find much material on this particular subject.