Starting in season 8, it would have been great if they had brought back Mr. Beauchamp (S7E1) and used him as a senior. The writers said they really struggled trying to incorporate a senior in seasons 8-10, which is why the role (mostly) become a much more minor part of each episode.

I think it would have been great to see the interchanges between Mr. Beauchamp and Mr. Humphries for even one episode, and even better if it had lasted an entire season.

The actor (Jeffrey Gardiner) had already appeared twice in AYBS, once as the potential new-hire candidate in S7E1, and again in S5E1 when he comes in and attempts to buy gloves while Mr. Grainger pretends to be a customer.

During S3E6 "German Week", it's mentioned that there was a "Russian Cosmetics Week" that they attempted at some point.

It would have been interesting to actually have this turned into an episode.

As many fans have brought up in the past, the "Grace Brothers Christmas Parties" seem to be the stuff of legends.....especially after S4E6.

It seemed to be implied that the parties were conducted elsewhere outside of the store.

However, I think an entire episode could have been written about one of their parties that takes place on the department floor. This may have been a great season finale for season 5, just like S3E9 or S4E7.

It would have been great fun to have an entire episode centered around Mr. Harman. For example, perhaps they need someone to take over on the men's counter temporarily while one of the staff goes on holiday.

Since Mr. Grainger has been there for quite a long time, he might have several days off saved up that he wants to use. He decides to take off for a week, and as a result Mr. Harman is chosen to take over in the junior position until he returns.

Mr. Harman, of course, dresses up in a suit and tie while working there.

A great scene would have been Mr. Harman switching roles with Captain Peacock. Perhaps packing and maintenance need help bringing up a large center display stand to the department floor. The store is busy, and so all the sales staff (including Mr. Harman) are attending to customers.

As a result, Captain Peacock has to go down and help them out. While he's down there, he doesn't want to dirty his clothes so he wears a maintenance uniform over it.

Captain Peacock now comes on the floor, dressed in a maintenance uniform, and Mr. Harman very happily comes over and tells him he's not allowed on the floor during working hours.