So give the top two or three (or more) reasons for loving this show.
Here are mine:
No wrong answers here, and repeating someone else's reasons is perfectly OK.
I like the fact that there was almost always a moral lesson woven in with the laughs
The many humorous mentions of food, from bubble and squeak, to sawdust meatballs, to having your main dish concealed in a heavy sauce, etc., etc., etc.
Kerosene cucumbers, apple pie, big chicken dinners, and spaghetti made with the secret ingredient.
And the Businessman's Special!
A hollowed-out tomato stuffed with avocado and raisins. And top things off with a lemon phosphate and you're right in business!
All of the above, PLUS, it just plain makes you feel good.
I was 12 when the show began and I have watched many episodes per year since that time, TAGS is like being with and old friend.
For me, I think it is the sense of community (which ties in with Dud's answer concerning the moral lessons). I like the way that everyone looks out for each other--even when a particular person is a bit annoying and maybe not always so kind in their own right (I'm looking at you Clara). Think of the episode where Barney arrests the whole town and gets ridiculed. They were in the right--Barney overreached (to say the least--arresting the mayor for vagrancy, etc.) and yet when they discover Barney is going to leave the sheriff's office they voluntarily return to the jail. Gets me every time I see it. Even Jubal (almost as close to a real villain as you get in TAGS) redeems himself a bit by helping Barney stumble toward the squad car when he "accidentally" imbibed some of his moonshine (I write "accidentally in scare quotes because after he realized it was not water he went back for plenty more). I like the underlying assumption that community is precious and ought to be preserved.