For about a decade, my family had 3 cats. Three cats seemed like a good fit for us. They got along well. We loved them dearly, but then the inevitable happened. The two eldest became older, and eventually passed.
For the past 2 years, we have had a series of cats coming and going, some partly due to us becoming fosters and two because their owners died, and had no where to go. One was adopted, the other was a sick senior who passed last year.
The last of the first three, Abby, died earlier this summer. We had already gotten a pair of kittens two years ago, Luke and Lily. Our current fosters have been with us for almost a month and we have become very attached. Not just us humans, but Luke and Lily too. Luke, my high energy cat, is delighted to have kittens to entertain him and play with. Even Lily is getting in on action, running around with them in the morning. At 6 am, our living room and hallway seems like a cat race track with cats zooming this way and that way, ending up tangled and play fighting. It's pretty awesome to watch as I'm quietly sipping my coffee. So, yes, we've decided to adopt our current fosters, Josh and Maya (pictured above). Four cats are a good fit too.