I respect Bryston for building their amps like tanks and backing them with a 20 yr guarantee. I sent my Thiels back to Thiel twice in 20 years, and they fixed them up both times for nothing. Unfortunately, Thiel was bought out and driven into the ground. Magnepan also backed up their product when I was a Maggie user in the late 80s-early 90s. Vandersteen has a reputation for standing behind their product.
Another departed company, Adcom, offered good value for money. I still have a 1990s-era Adcom amp. Cambridge Audio offers reliable and relatively good value. Elac seems to be trying to occupy that space as well.
My most recent purchase was a pair of Harbeths, and I viewed the near-cult following and reasonable (non-BS) engagement of their CEO, Alan Shaw, as positive indications. It's nice to buy things that both sound good and are sold without nonsense (albeit at a premium price).
I don't claim any of these are definitive, just my impressions. I've owned one or more components from each of these companies except Elac and Vandersteen.
Other names I've owned - Conrad-Johnson, VTL, Spectral, Cary. All a long time ago, but I still have the VTL Deluxe 225 monoblocks with a full complement of KT90s if anyone is interested. Tubes seemed pretty cool, but in the end I didn't get the bug.