Magic Russ
Soniccouture has a lot of nice sounding chromatic percussion, vintage keyboards, and a few oddities.
 
Hideaway studios is another favorite of mine.  Dan Wilson has a business restoring keyboards and samples some of the rarities he encounters.  He also had a series called the Blue Zone which was largely what happens when MacGyver goes into a music studio ( "I hooked my doorbell into a military surplus radio and ran it through the ensemble unit of an old ARP string machine...")
 
Precisionsounds has a wide variety of ethnic instruments and grandma organs.
 
I like the Scarbee Rickenbacker, but was a bit less impressed with their P-Bass.

Same here. A big bang for the buck. I plan to own all of them.

Don't forget Hammersmith Pro for Pianos...
Keepforest has some nice libraries also for Epic Cinematic things...

Kontakt is definitely "The" sample player for sheer number of 
exquisite libraries available for it.

Darn! I forgot to mention Indiginus. Blue Street Brass is excellent, inexpensive and easy to use. The guitars are great value too.

Impact Soundworks Celestia and Sonic Ocean and Sonic Forest. Almost any Hideaway Studio but love the Chroma. The Giant and Una Chorda are favs. Abbey Road 50's Drummer. This does not have to be used for 50's rock. It has a very present (and intimate, if you want it) sound that can be used for anything. Great drums for Indie and just as good for Jazz. Jazz? IMHO. I bought it before it was in Komplete Ultimate. I'm glad I did. If I would have gotten it with KU I probably wouldn't have got to know it. That can happen with Komplete or KU.