If you were to pick up your phone now and call a friend, or perhaps a colleague or your barber etc. and say to them, "Hey Ian, I'm just calling to - it's Gary... Gary Haskill? You cut my hair?... yeah hi, I'm just - what do you mean, where'd I get it from? It doesn't matter. - No, I don't think it's weird to have your barber's phone number... Well, I'm just calling to ask what you think the best television show of all time is? 'Ready, Steady, Cook!'? - Thank you very much." If the recipient of your call appears slightly less reluctant to engage you in conversation, and doesn't seem to be making any suggestion that they will report you to the police for harassment should you call them again, then perhaps you may want to have a slightly more engaged discussion on the matter than I managed with my - now former - barber Ian.
The person you talk to will almost certainly give a different answer for what they consider to be the best TV show of all time. This is because they almost certainly spent their time productively during the mid-2000s and not just sitting around watching day-time television when they should've been learning how to cut hair properly. They may even say that it'd be impossible to claim one particular show as 'the best of all time', as it's too subjective that. While they could certainly say their favourite show of all time, it would be pointless for them to try assert what is, objectively, the greatest show of all time. If they go down this pedantic road then you ought simply alert them to the various review aggregating websites that exist and tell them to take their argument up with IMDb.
For IMDb has spoken and there is a new claimant to the crown of 'best tv show of all time', and that is Sky Atlantic and HBO's 'Chernobyl'. The mini-series, centred around the 1986 Chernobyl disaster, has been garnering rave reviews and currently sits top of their list of the 250 highest rated television shows of all time. It has a rating of 9.5 and has just knocked Planet Earth 2 of its perch at the top of the list.
So, while you now go off to watch, the apparent greatest television programme of all time, I have a call to make from a payphone to a certain barber to illuminate him on just how wrong he was, as Ready, Steady, Cook! didn't even make the top 250 in the list.