IMO, Mars is the largest body we'll land on. It also has a tangable atmosphere which would affect design. Let's design a SSTO craft capable of landing on and taking off from Mars. Since the mothership will get it to Mars orbit, all it has to do is deorbit and land, then take off again and dock with the mothership in orbit. Designing a SSTO craft for Mars would be far easier than one for Earth. This baseline design could then be easily used to land on every other body of interest (Moon, Phobos, Demos, Titan, Europa, Triton, NEOs, etc) in the solar system.

In between missions, while the large ship is in spacedock, the shuttlecraft can be brought down to Earth to be refurbished or replaced as needed, then launched on a large rocket back into orbit. Or they could be refurbished on the Moon. This is why we need to invest in heavy duty robust space infrastructure, and start getting away from the single use disposable equipment we have today.