What sounds best integrated or separates?

I agree 100% with Arthur. Add speakers and budget to his list.

There are some exceptional integrated amps: Ars Filarmonia, VAC Phi Beta, Jadis...

They don't necessarily take a back seat to any separates if matched properly to speakers and room size.

Integrated separates.

To manufacture large power separates is less costly than same with large power integrated due to the power supply complications for preamp and output section of the amplifier.

A smart buyer can find high quality separates on Audiogon that when mated together, can outperform any integrated at the same price point. For example, find a Forte 4A amplifier for $600-$700 and a Modulus preamp at $800. There is not a $1,500 integrated on the market that can match this sound. One recommendation: don't cheap out on the interconnect, but keep it as short as your set-up allows, and consider putting a line filter on the cable to kill RFI.

Uraniumcommittee; I know what you mean about integrateds being low in power (so, cheaper) and thus not as good as separates. Do you mean something like these?

Zanden

Audio Note

Or, even my system.