Nothing says it's the holiday season like a brand-new Amazon device. Amazon has been expanding its product lineups left and right this year, from its speaker options with the revived Echo Spot to a relaunch of the entire Kindle line (with some hiccups). Now the Echo Show family is getting a big update. Literally--it's getting a massive, 21-inch device added to the roster. The Echo Show 21 ( 400) is the newest member of Amazon's vast list of Echo-powered devices, with a 21-inch display.

Amazon's Echo Show smart displays with Alexa voice control are already a good value next to the competition, but a bunch of deals are making them even cheaper. The Show 5 is the best one, on sale right now for just $40, or 53 percent off the regular price. And if you want a larger screen, you can find great deals on the Show 8 and Show 15 -- including a free Show 5 with the latter. The Echo Show 5 scored a very solid 85 score in our Engadget review, as it's small size is ideal if don't have a ton of space on your desk, nightstand or countertop. It has a 5.5-inch, 960 x 480 resolution display that shows things like weather forecasts, calendar events, photos and more.

Aside from Black Friday, Amazon Prime Day is the best time of year to pick up an Echo device since most of them are deeply discounted. Amazon didn't disappoint this year -- all of its Echo Show smart displays are on sale for Prime Day, key among them being the Echo Show 8 for $75. Also on sale are the Echo Show 5 for only $35, the swiveling Echo Show 10 for $180 and the Echo Show 15 for $180 as well. It's the second-generation Show 8 that you can get for $75, and we gave it a score of 87 when it came out last year. We like its 8-inch, 1,280 x 800-resolution touchscreen, minimalist design and solid sound quality.

For the first time since February, Amazon has discounted the Echo Show 8 to $90. We gave the second-generation model a score of 87 when Amazon released it midway through last year. We liked the Echo Show 8's vibrant 1,280 by 800 resolution display and handy video calling functionality. It comes with a digital pan-and-zoom face-tracking feature that follows you while you move around. Best of all, that feature works with every video chat platform available for the device, including Skype and Zoom. In addition to discounting the Echo Show 8, Amazon has also put the Echo Show 15 on sale.

The Echo Show 15 is Amazon's biggest Alexa smart display and is designed to be a command centre or digital noticeboard for all the family. It is considerable larger than the rest of Amazon's Echo Show devices, which were recently given a motorised screen and small desk-ready displays. That illusion is furthered by its wall-mountable form – it is designed to be hung in a central place like the digital equivalent of the pinboards common to kitchens of homes of the 1980s, and can be mounted in landscape or portrait orientation. It can be bought with a stand for £30 more if you would rather not screw 2.2kg of technology into your wall. The 1080p touchscreen is bright and crisp when viewed at arm's reach.

Amazon's Echo Show line has been around for four years, but until now the screen sizes have ranged from five to 10 inches, making it ideal as a multipurpose bedside alarm or a companion screen in the kitchen. The 15-inch Echo Show 15, available now, is by far the largest size Amazon has attempted, and it's also notably the first Echo Show you can mount on your wall. Because of that, the company is betting some people will use it not just as a digital photo frame, but also as a family bulletin board. If that's specifically what you want out of a smart display, the Echo Show 15 could be a niche but very fitting match. Somehow, though, we suspect that's not most people.