Mixed Brand Pre-Amp Power Amp Pairings that Work

I am thinking of and starting from scratch and revamping my pre-amp to power amp chain. I know that the performance of these two elements will be tightly coupled, so they need to match.

I suppose the easiest thing for me to do would likely be to stick with one brand (potentially even an integrated) and assume that they have optimally paired their own components to work well together. But even if I ended up getting pre- and power from one brand, I would want to do some thinking about the best pairing.

I would love to hear from folks here with more experience than me with off brand pairings. What worked? What didn't? All thoughts are much appreciated