Isolated RS485. I seldom bother with terminator resistor on RS485 because I never have errors due to this below 10 meters. Bias is a different issue as I experience problems without bias resistors on one side even on very short distances.
The main difference between RS485 and CAN is that CAN uses arbitration and is depending on better timing. RS485 is in contrary much easier to get working even with lousy solutions and cabling.