Was obsessed with this show when I was a kid. In fact, one of my best mates to this day was a kid I happened to get sat next to when I had one of those nightmare secondary school transfers (halfway through a year), and we immediately got chatting about Red Dwarf and bonding over it. Between us we had every series on VHS.
By recollection, the first 3 series are funny-but-dated, series 4-6 are Properly Good and then it’s patchy-to-awful from that point on. I checked out after Series 8, but haven’t been back since so could be completely wrong on all counts. The nosedive it took was attributable to the writing team who created it “doing a Gervais-Merchant” and splitting up, but then one of them deciding to continue it without the other.
They also co-authored a couple of novels which were simultaneously a novelisation of the series and a massively detailed exploration into its wider universe and the character’s back stories way beyond what the TV show’s budget could ever have allowed. I read that Omnibus edition so much that the book literally disintegrated. Again, I remember it being fucking great in a sort of Terry Pratchett/Robert Rankin way but there’s 20 years of nostalgia in blurring my vision.