Nice idea for a thread indeed !
Same as OP, Noise Engineering is the first manufacturer that come to my mind when talking about positive experiences. I personally discussed with Markus a few times, I believe he's the guy behind the company's excellent blog, one discussion is enough to understand the company is populated by passionate people who care about the community around them.
I will add another couple more to the list:
- the people at Shakmat are generous with spreading knowledge and they're very friendly. I had the pleasure to meet the team at an event where I built one of their kits, the best part was definitely the conversation that came with the kit building.
- I had issues with Intellijel modules but their support was above standard IMHO, they fixed everything super quickly and were very friendly.
--- Voltage control all the things ---