jumper wires better for VCC or ground?
Generally speaking, you want the best signal integrity on your ground network, because signals as well as power are referenced to it.

That said, it is not necessarily true that a narrow trace on a single-sided PCB is better than a wire jumper or zero-ohm resistor in terms of its impedance. A 1-mm trace on "1&nbsp;oz." (35 &micro;m) copper is roughly equivalent to AWG30 wire, whereas soldered jumpers are typically AWG22, which has 1/6 the resistance.

Of much greater significance is how well you bypass or decouple the power on each chip. You want to use the most direct path possible between the capacitor(s) and the power/ground pins of the chip.