Outside of tube connectors, some of the best I've found are KLE. Pricey, but super easy to solder and have a very nice sound.
If you need to use binding posts, as I have to do*, I'd recommend using WBT binding posts. (*-my speaker cables are Shunyata Research Alpha v2s, and are too heavy to use with tube connectors).
WBT is
very widely-regarded in the speaker manufacturing industry, and makes a wide range of excellent binding posts with excellent engineering specifications and various price points. Link to WBT:
http://www.wbtusa.com/pages/0763m.htmlHere's the WBT - 0705Cu

Description:
WBT's flagship terminal with compact design. Equipped with filigree signal conductor made from pure copper that is directly gold plated and constructed on the nextgen principle. Grants highest conductivity. Fully insulated. CE and IEC conformant. Accepts 4-mm bananas, spades as well as crimped cable ends up to 4 mm² (11 AWG). Outer metal cap with platinum finish.Also, if you need speaker cables, I'd also recommend Danny's GR-Research speaker cables, as well. Excellent design topology and excellent quality materials used for the conductor and dielectric (insulation), as well. Here's the higher-spec 24 strand cables, but 16-strand are also available at a lower price:
https://gr-research.com/product/24-strand-diy-audiophile-speaker-cable/