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

+1 to Canare 4S11. Replaced Nordost "flat" speaker cable and I think they are better (at least not worse).
All my power cables replace with Signal Cable - not sure I can hear the difference, but they are well made and not pricey. For long runs to my GE Triton 1s I got Pangea from Audioadvisor - good looking and 69 bucks for 4 meter cord, not bad!
All my other cables are Blue Jeans, good stuff.

After trying many Straightwire lower end speaker cables i found that the Crescendos were the absolute best also use there Crescendo XLR and RCA interconnects. To me you will never ever want to upgrade from these. 

Straightwire Crescendos cost thousand of dollars. If they are "budget" then what is not ))).

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