Red Dwarf
There are few shows that can do space comedy for any length of time. Most of them become stale when they run out of material to parody.
Red Dwarf is an anomaly. It shouldn't work. THe story of a man frozen in time for 3 million years on a desolate ship with a resurrected crew member, an evolved cat, and a daft computer should not work. But it works, and works in surprising ways. Add to that the android Kryten later in the series and you have one of my favorite show of all time.