I have done:
YVR-LAX-LHR-ZRH-IST-JNB-CPT (one direction)
CPT-JNB-ZRH-GVA-JFK/EWR-YVR (one direction)
Both continuous with stopovers of 5 hours or less, and more than 40+ hours total in each direction, and all J Class

YVR-SFO-JFK-LAX-NRT-SIN (one direction)
SIN-NRT-LAX-JFK-SFO-YVR (one direction)
Both continuous with stopovers of 5 hours or less, and more than 40+ hours total in each direction, and more than 40+ hours total in each direction, and all J Class

I am about to do in December:
YVR-SFO-HKG-IST-LAX-YVR (courtesy of TK CC Deal)
One continuous around the world marathon in 62+ hours, in either CC (TK) or J Class