Who makes budget speaker cables which are truly “good” or “exceptional” in quality?

Would never use anything but Crescendos , compare them to cables as much as no dollar limit and you will agree that they are budget

Rivercable.com has great sounding speaker cables with built-in banana plug twist locks. They matched my magnepan 3.7/1.7 speakers the best with ATI 6005 amplifier. They are made really well, come with a cool birth certificate with a 30 day return policy. Their performance exceeded other budget cables (blue jean, emotiva) and matched any 2K cables I have tried in my system (Nordost, Synergistic research, wire world) 
Flexigy 8 model is a thick flat cable, which I run under the area rug for my 1.7 surrounds. 
http://www.rivercable.com/flexygy8.asp

I second Dueland from PartsConnexion.com
2. Supra Cables
3. audioquest
4. Kimber Kables
5. Canare
however having spent thousands on IC and speaker cables nothing really beats Dueland cables from from Parts Connexion

The Schmitt cables sold on here are excellent in tone and resolution AND, bring a lower noise level to the party than any other I've heard , A revelation at low price .

Call me a HiFi pleb, but try "Ugly Cable:  https://www.uglycable.com.au/ and go for a reel of 16AWG OFC cable and you then you can spent big on the connectors.