Ditto on all the Ryobi li-Ion tools mentioned above. I also have the impact driver (deck screws etc) not the impact wrench (automotive).
Their 18 volt chainsaw is ideal for my use in this apple orchard. I no longer own a 2-cycle saw, don't need it. Most anything I want to cut up is dead, fallen, punky, and it goes through that like butter. Last summer I had to deal with a dead and leaning Eucalyptus, it did ok in that hard dried wood. And I cut up a fallen fresh Eucalyptus that was blocking a lane, as far as I could go with the 10 inch bar. That one worked the saw as hard as I think it can take without hurting it. A neighbor with a commercial size saw and splitter cut up the rest of it down to the 36" base, to take home for firewood. I would never use a 2-cycle saw like that in a decade, it would be cheaper to rent one if I ever needed it - and no fuel mix to store here.
I'm sold on Ryobi for my intermittent farm projects.
One tip, batteries and chargers are less expensive if you get them in a kit with the impact wrench or something. And Homelite gear uses the same battery, I have two of their hedge trimmers that I found in a thrift store @ $5 each.
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Added: Since the OP asked about yard tools I should add some emphasis to that. I use the Ryobi 18v string trimmer frequently. Just grab a battery and go, no 2-cycle fuel to fuss with. It's easier to keep up with minor spots since there's no overhead to get gas, blend it, refuel, storage, all that.
I also like the Homelite/Ryobi (maroon color) hedge trimmer. It's not quite a powerful as my corded one but it's a lot quicker to set up and go.
If you wouldn't use a chain saw enough to justify buying it, the recripro saw in Ryobi's combo kit sure beats a handheld pruning saw for occasionally cutting back limbs. Or even the little circular saw, if your branches are straight so you can get the saw in there. It cuts well, and faster, but the recipro saw fits into more places.