I have a corner of my house that has water draining in under the house. It is a ranch style house with concrete around this corner. I added some quikcrete to the main area, but the whole 5ft by 10ft corner has broken concrete where water is pooled and continues to do so. I want to concrete the base so water slopes away from the house. What is the best way to do this. Hydraulic cement mixed with rock sand, or should I just keep using the quikcrete.

I'm not getting a clear picture of the 'broken concrete' area - an area 5 x 10 that was poured flat on the ground at a corner, to keep water away from the foundation? Is the foundation itself crack free? Is it leaking, or damp, inside?
You can't just keep pouring good concrete on top of bad. You need a deep sand and gravel base under it, with pounded earth under that.
You might be better off just taking away all the broken concrete, going down 2 feet, and installing proper trench drains wrapped in gravel and landscape cloth and buried. And if you want to get really current, you go to the bottom of the foundation and install footing drains the same way, and put waterproofing (the new bubble kind) on the outer walls. And after all that is done, run gutter downspouts away on the surface, not underground.