I agree. I love the Henry McGee episode with him as Seymour. I also like the episode where they suspect that someone has broken into the house. Actually some of the best episodes take place in the final series, by which time Richard Beckinsale had already left the show.
It proves that they should have done that final series regardless, as it was still good. Just a shame he wasn't in it, but the idea still had places to go without him so it was all good.