We've got a Stihl MS211C (never used), a Stihl MSA140C-B (just bought it, will try it soon), a Stihl GTA-26 (a cute little thing that is surprisingly useful) and Black & Decker Alligator lopper (we've used this for decades, and it is a cheap and phenomenal tool IMHO).
The 211 is a gas saw with an 18" bar. We've got chaps and helmet and all that stuff, but it's a bit intimidating for not-really-chainsaw-using folks like us. Many years ago the wife said "I want a chainsaw for Christmas". I was thinking, "What do we need a chainsaw for, we live in the suburbs?" But it wasn't terribly expensive so I got the Stihl MS211C for her, along with the safety gear. Being suburbanites, it's not like we live in a forest of huge trees. Yes, we have quite a few trees in our yard, but once you cut 'em down, well, they're gone. So no need for a larger chainsaw like this. But we have it. For whatever reason.
My wife just bought the 140 a few weeks ago. 12" bar I think it is? She brought it home to yet another "What do we need a chainsaw for?" question from me. Hey, but this one is battery powered, FWIW. I guess that means we don't have to worry about it starting or not starting the next time we don't use it. But the battery interchanges with the new Stihl leaf blower that she bought at the same time. That's a pretty good leaf blower BTW. We also have a corded Stihl hedge trimmer. No hedges mind you, but hey, we're ready to trim them if one should pop up in our yard. That hedge trimmer is quite the beast. It munches through some pretty heavy evergreen gnarly stuff, which is what we trim with it. Lastly (in the Stihl group, except for the itsy bitsy saw below), we have a gas powered weed whacker. I use that to scalp the yard down to the dirt when I miss the actual blade of grass I was aiming for. That's one powerful sucker!
Now the little chainsaw thingys we have - we do use those all the time. That little Stihl GTA-26 is great for trimming branches with it's 4 inch bar. Very handy. Like a little hand saw, but powered, so it's effortless. My favorite chainsaw thingy is still our ancient B&D Alligator loppers. That has a 6" bar on it and it clamps down on what you're cutting. So no kickback and very safe because of that. And the lower jaw snaps closed over the chain and bar under spring tension so you'd have to work really hard to cut yourself with it. Ours is corded, but they make battery ones now.
If I could only have one - it would be the B&D alligator loppers. This is one of those tools that you buy a spare of, in case yours breaks and they stopped making it. I'll bet that 140 saw would be great for people with lots of trees that need clearing. But we don't really plan to denude our yard, so I'm not exactly sure what my wife bought it for.
Our Fellowship of the Chainsaw: