What are Your Favorite and Most hated Record Manufacturers

As you're sure to know Mike, I am tempted to say none, because pressing is such a crapshoot. But then thinking about it some more, I have no idea who is good in terms of new or current production. Historically however, which to a certain extent carries on to this day (to the extent, if any, they are still pressing!) the good ones are:Reference Recordings 
AudioQuest 
Sheffield 

These are the only ones with consistently high quality. In my experience.  AudioQuest label is not well known but they did a series with great blues men like Doug MacLeod and Sam McClain featuring all high end AudioQuest cabling in the recording chain.

Sheffield has consistently superb recording quality and flawless pressings. Michael Ruff Speaking in Melodies is a true desert island LP.

As for the worst not even the internet has room to list them all.

With respect to companies still pressing LPs, I've had generally good experience with Acoustic Sounds, Mofi and Analogphonic.  Generally bad luck with Yarlung Records.

Bear Family (Germany), Sundazed, Harmonia Mundi (France and U.S.A.), Ace (UK). 

rshak, Acoustic Sounds is Analog Productions. MC, Reference Recordings is still going strong and making great product but the others are sadly extinct. Yes John, Ryco is now owned by Warner which is more than likely the problem. I forgot about Sundazed. I'm pretty sure all my Sundazed records are high quality. Bear Family is a store specializing in Pre Beatles music. They do not make records.  Yarlung is very small doing only craft music. MoFi does OK for the most part.
Oh and MC go to Analog Productions and buy the record by Janis Ian, Breaking Silence. I promise this record will give you a new standard for recording quality never mind the 11 great tunes and her voice. 

Mike

Lol! Mike I bought Breaking Silence a good 25 years ago! Yeah its a beauty! I've acquired a stack of beauties over the years but back then it was a standout. Its so good its good even on CD! Its so good I would carry it around just because it was so darn much fun to be able to make anybody's stereo sound better just by playing Breaking Silence. One time me and my wife are sitting in the back of a Subaru, I passed it forward said put this in, and then we looked at each other with the grin of people who share a secret. Yeah its so good it makes even a Subaru sound better!

But wait, there's more! You hit the motherlode, Mike! Everyone should have this on their shelf. Because it was Breaking Silence that delivered the knock-out blow that convinced me I had to go analog. Was in Definitive Audio where they had some little Linn system set up on a wall. We played some random record they pulled out of a bin. Literally a bin. Literally some random record. It was impressive how good it sounded. Deep, expansive, which even more amazing seeing how the system was set up. 

Okay so then the sales guy thinking he will impress me says listen to this. And he loads Breaking Silence into this Mark Levinson CD player with Mark Levinson amps and speaker cables thick as my arm and Wilsons, easily five if not ten times the system cost of the little Linn. Knowing at this time how awesome this recording is I was shocked, stunned and blown away. Because if all this expensive highly respected gear still can't manage to make one of the all time great recordings sound as good as some random record bin LP, well then I need a record player.

And the rest is history.