Call me lazy if you want to, but I like these light-weight cordless chain saws for small jobs. Heavy pruning, for example.
Sure, I have regular pruning saws, but those electric things are nifty. I go with Ryobi because I already have all of their betteries and chargers for blowers and trimmers.
For heavy-duty, I do have a Stihl Farm Boss which I love to use, but it is overkill for small jobs. For example, I have overgrown lilacs. Neglected to remove 1/4 or 1/3 of their older main stems annually. 3" thick now.
You can find all of the mini-chain saws on Amazon.