Can anyone think of episodes that included a breakfast scene? I think there were more of them in the first few seasons.

Here are a few from the first two seasons:

Season 1:
Man Around the House (Pilot)
It's Only Money
Jack the Giant Killer


Season 2:
Ground Rules (two breakfast scenes!)
Helen's Job
Bird Song

I always loved to watch them eat together or be in the kitchen together actually "doing" domestic things. We rarely ever saw them doing other everyday stuff, like laundry or taking out trash, etc. Sometimes we saw them cleaning but that's about it.

Going off topic but another interesting fact is that from season 7 onwards there weren't any scenes in the bathroom either, probably also has to due to the fact that in those 2 seasons they moved filming locations and I guess the producers didn't want to chip in having the bathroom remodeled.

I agree, and I also think there were more "domestic" situations in the first half of the show because later on they filmed outside the apartment setting---like Jack's Bistro, Angelino's, etc. In the first few seasons all we saw was the trio in the apt and at the Regal Beagle.