Thin, Flexible & Inexpensive Speaker Cables?

It's hard to recommend without knowing where you want the sound of your system to go but for budget cables Audio Quest Type 4 or the cheaper Kimbers.

Russ69: I want it to sound neutral

What about some Dueland  cable.  It is very reasonable and sounds very good.

https://www.partsconnexion.com/duelund-speaker-cable.html

Signal Cable Silver Resolution is thin and high-quality for the price.  Not sure exactly what you consider "thin", but you could also try some 12-gauge Belden from Blue Jeans Cables.  They do pretty nice terminations too.  

http://signalcable.com/silverresolutionspeaker.html

I tried Canare 4S11 cable for awhile after trying a Benchmark AHB2 amp. I also used the Benchmark spk. cable(Canare) earlier for an audition. I then read a comment by "Duster" on audioasylum who has since passed away but he was always asked for cable advice from the members. He suggested Furez a 12ga. double run cable >making a total of 9 ga. OFC 99.997 copper. It has over 200 strands per leg of various 30 ga. and 24 ga. wire with a teflon like coating vs pvc.. It cost me 1.70 per ft. I covered with techflex and then used the suggested banana plugs> Viborg pure copper with rhodium plating and they fit very tight. My total cost 9 ft. pair was around 120.00. I like them actually the best sprk. cables I have used in many years. I am sure the mega bucks cables are better but only if you can afford them.  Another suggestion GR research kit cables like the Kimber 12tcs. Depending on length less than 300.00. Good luck in your cable hunting. 

https://www.amazon.com/Tuneful-Cables-Belden-9497-Speaker/dp/B08S6N4BC7

these work well for me

Mogami cables are used in many recording studios. They're thin, flexible and durable. Because of their use in & out of the hobby, you can often find better dealers thru musical instrument dealers. They've outperformed many higher priced cables in my system and numerous friends'. 

Grover Huffman is also known for very high value flexible cables. Depending on model and length, they may come in under $300. Cheers,

Spencer