Tough question but again depends on what you are going to use it for.
24-70 2.8 is my primary working lens for weddings.
if you already have the 70-200 this give you a complete range for 2.8.
I would start with these two lenses.

Now with that said the 24 1.4 gives you so much more as your first prime. It is great in low light and I can shoot indoors with no flash with ease.
Dealing with natural light and no flash will set these photos apart from the rest, not to say the bokeh at 1.4 is amazing.
This is not a portrait lens it is too wide, but it is indoor and outdoor low light fantastic.
I would not start with 35 or 50 for my first prime unless you are tight on budget. (if you are tight on budget then you may need to go to the 50 1.4 and bypass the 24 for now)