Best 5.1 ONLY receiver every made?

Hi everyone!

I am curious to get your opinions about what the best used 5.1 receiver is. I had a 7.1 one setup about four years ago, but eventually left surround sound for a stereo setup. Now that I have space for both I am considering venturing back into surround sound.

So my question is... who made the biggest, baddest, and best sounding 5.1 receiver in the past that would now be a great buy on the used market? I see some of the new flagship receivers from Yamaha and Denon are pretty monstrous, did they have 5.1 counterparts back in the day?

Thanks for your thoughts,

JML