True 8 Gage banana plugs

These are what I use and they work great FURUTECH FT-212(G) hi-performance Gold-Plated/Pure-copper Banana plugs-set of 4 | eBay

Check any of the Furutech banana plugs they will take up to 5.5mm wire diameter, which is around 4 ga. so 8 ga. wire is an easy fir in the Furutech banana plugs either straight or 90 degree also the 90 degree plugs spread open when you tighten the screw so that they stay tight in your amp or speakers.

they are somewhat expensive but your get what you pay for, they are top quality plugs.FP-202（R）/（G） | FURUTECH

Thanks to all for their good answers!  You guys are great! 

WBT-0644 banana plugs (they have newer version of the 0644 but terribly expensive)

Or you can get some Chinese brand Audiocrast banana plugs 10mm ID for $15 on amazon or ebay.... identical!!! i don't find any audible difference... only 20x cheaper than the WBT