How do I choose the right platform for my website?

Ask ten people and you will get 12 different answers.

What is the purpose of the site? Do you have previous skills? What is your monthly budget? Will you need fancy features or a blog? How much spare time to build and maintain?

To get the ball rolling I say WordPress. Can start for low cost, extend with themes / templates as fitting a base brand and extend as needed.
Also biased as I do WordPress hosting.