My volume and tone pots are noisy. I have already sprayed them with contact cleaner several times, but it only lasts for a few weeks, now.

I cleaned them again yesterday really good, but the volume pot is still not working right. It is not cutting all of the way off anymore.

I want to put in new pots.

What are the best pots and capacitor value for Strat, volume and tone, 250K volume and 500K tone?

I want to get some really good ones.

What is the best brand?
250k for single coils. 500k if you have a humbucker in there. .022µF or .047µF for the tone cap, your choice. Alpha is pretty much the standard. CTS is usually better but one of the users here got a whole batch of bad ones. I'd go with Alpha.