need some help with the power wires and the ground

on my aftermarket stereo it has
constant power
ignition power
ground
power antenna wire (which can be used for the remote for the amp right ?)

OEM unit has
constant power
ignition power
chassis ground
and another wire that runs to the fuse box (2nd ground ?)

now im wondering where do I plug my stereo ground, right to the chassis ground or to the wire that goes to the fuse box if that is a ground