That is a tough question to answer.......it depends on steel type, heat treat, main grind angle, edge thickness just before the edge bevel.......lots of variables. Including the biggest variable, the operator. Are you delicate and surgical, or a bit ham fisted?
For light duty(no chopping or prying around joints etc.) with good quality steel and heat treating you can go super thin.
There really is no "best angle", just different angles. Testing is the only way to determine what is ideal for your knife and situation.
Darcy