I've been very, very happy with my MacBook Air, which I picked up in 2013 and which sailed by its three-year milestone with flying colors, no less capable now than it was when I first got it. It is, without a doubt, the best all around computer I've ever bought. That's not to say it's the most powerful (it isn't, and never was) or best featured (though it might be, if I consider all the apps I use on it that simply don't exist for Windows or Linux). However, for writing and all but the most demanding video stuff I do with a computer, it is my preferred machine. (It's been so good I invested in additional desktop Macs that I otherwise wouldn't have looked at twice.)
With that said, I'm not sure it's the absolute best value-to-cost computer we have in the house. It's a near thing, because I do use use the heck out of the Air, but I think the award might have to go to the Chromebook we picked up a few years ago for Sean. Like the Air, it's been around for a few years, is aging gracefully, and gets more and more use as time goes on and Sean grows more adept with it (so its cost-to-value ratio grows ever more favorable). It cost us $150 bucks at the time (thanks to some Amex points we had stored up), and it's been great.
This Christmas will see a new contender for the Value-to-Cost throne in our house, as we're getting a new Chromebook. It just showed up today, I had a chance to play with it check it out and get it set up for its intended users.
The machine in question is an Acer R11 Convertible. It's a solid Chromebook (same brand as Sean's current machine, though smaller) with (basically) a 10-inch touchscreen that you can flip over and use as a tent display or a nice tablet, with 4GB of memory, and 32 gig drive, all for less than $300.
Two USB ports, HDMI mini out and SD card slot. Battery life is supposed to be in the 10 hour range (we'll see).
And, as a huge bonus, this is one of the models that can run Android apps natively, which means I can install stuff like Jotterpad, Firefox, Skype, Lightroom, and even some cool Android ports of games like Final Fantasy Tactics. (!!!)
All of which is to say that if you’ve been waiting for a perfectly good Chromebook that you can also use as a perfectly good tablet, for under $300, this thing looks pretty good.
Amazon.com: Acer Chromebook R 11 Convertible, 11.6-Inch HD Touch, Intel Celeron N3150, 4GB DDR3L, 32GB, Chrome, CB5-132T-C1LK: Computers & Accessories