Prime Only Setup

I will start by saying I do not own any DSLR or any camera except for my phone. I am mildly interested in photography and like to "play" with my brother's T3i. I would say it is quite apparent that choosing lenses can be confusing, even more so when your wallet is thin and yet want to future proof your setup that is purely for hobby. So in a series of questions I plan to ask in this forum my first inquiry is,

If you had to go by three and only three fixed focus(I believe they are called Prime) lenses, what would be you choices? (I am assuming everyone would like brightest possible aperture. Whether you want to include price consideration is purely your choice.)