[Brightcolours]

In the past I was happy with my set of primes: 14F2.8 20f1.8 28f2.8 50f1.4 and 100mm macro.

I am reconsidering getting back there.

I sold the 14 and 20mm (I regret it) the 28mm has died. And now I Intend to go back.

What set would be ideal ? I am considering the 35mm f2.0 plus either a 20'or 24mm what do you suggest?

Not easy to answer, it depends on the focal lengths you think you will prefer now, and on which body.

 

The EF-S 24mm f2.8 STM is a nice little lens for your 750D, very compact and light. It will be kinda a 35mm FF equivalent, but will not work for the 5D, being EF-S. But for the 5D you can get the also very compact and light 40mm f2.8 STM, for same effect.

 

Wide on APS-C is where primes make less sense. I'd stick with the EF-S 10-18mm there.

For FF... Price and size/weight are possibly things to consider.