Samsung Gear S3 Frontier: Until we see what Google can pack into a smartwatch with its long-awaited Pixel Watch, the best smartwatch for Android users is the Samsung Gear S3 Frontier. It pretty much has everything a user with an Android phone needs in a smartwatch - GPS, heart rate monitor, water resistance, near field communications, an always-on digital display, messaging alerts and app support. I don’t see a real need to opt for the 3G version yet, which would untether you from your phone completely but adds around $100 to the price. ($549)
Samsung treads between smartwatch and fitness tracker, also packing in a heart rate sensor along with that GPS and its much-improved Samsung Health software. There's also the option of LTE (coming soon), if you wish for an untethered connection, with a standalone speaker for taking calls on the watch. It's now waterproof, too, adding swim tracking skills that are on par with the Watch Series 4.
The top smartwatches that debuted at the 2017 Consumer Electronics Show included the Casio WSD-F20, Misfit Wearables Vapor and the Garmin Fenix 5 series. Apple released on September 22, 2017 their Apple Watch Series 3 model which offers built in LTE cellular connectivity allowing phone calls, messaging and data without relying on a nearby smartphone connection. 
The Martian Passport wants to give you the best of both watch worlds, by offering a mechanical, analog watch face and a small LCD. If you prefer a traditional-looking watch and want the “smart” component to be unobtrusive, this model may work for you. It comes in three varieties, all with silver bezels: a white face with a black or white band or a black face with a black band.
348 x 250 Resolution Touchscreen Display/ Color LCD/ Dynamic Personal Coaching/ PurePulse Heart Rate/ Popular Apps/ SmartTrack/ Sleep Stages And Insights/ Store And Play Music/ Water Resistant Up To 50M And Tracks Swims/ Built-In NFC Chip/ All-Day Activity/ Built-In GPS/ Multi-Day Battery/ Multi-Sport Modes/ Smartphone Notifications/ Blue Gray And Silver Finish
Apple Watch (1st generation and Series 1) Apple watchOS No 8.2+ (1st generation) 10.0+ (Series 1) Apple S1 (1st generation) Apple S1P 4.0 LE ] From paired iPhone No Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes IPX7 Digital 1.7 / 1.5 319x390 / 272x340 AMOLED 1.5 250 / 205 Lithium-ion 42 mm / 38 mm 12.46 / 12.3 36.2 / 32.9 Varies Yes Yes No
While internal hardware varies, most have an electronic visual display, either backlit LCD or OLED or Hologram. Some use transflective or electronic paper, to consume less power. Most have a rechargeable battery. Peripheral devices may include digital cameras, thermometers, accelerometers, pedometers, heart rate monitors, altimeters, barometers, compasses, GPS receivers, tiny speakers, and SD cards, which are recognized as storage devices by many other kinds of computers.
All but the Martian Notifier claim some degree of water resistance: the LG, Samsung, and Motorola models can survive underwater up to 1 meter for 30 minutes, the Cookoo2 up to 100 meters, and the MetaWatch up to 3ATM, which is equivalent to 30 meters. Only the Martian and Motorola models claim to have scratch-resistant screens (the Martian has an anti-scratch acrylic crystal and the Moto 3 uses Gorilla Glass 3).
The Charge 2 was one of Fitbit's most popular trackers, so the company stuck with the winning formula with the Charge 3. If you're at all familiar with the Charge 2, you'll notice that not much has changed in the updated device—it's still a rectangular tracker hugged on its short edges by two parts of a band. Fitbit updated the connecting mechanism that lets you switch out the bands on the Charge 3, making it easier to press the black sliver of a button on either end to release the device's current band. The new band snaps right into place without any extra effort.
Why we like it: Fossil’s Q Explorist and Venture watches are good-looking watches with a decent range of case and band options, and decent responsiveness and battery life—this is high praise given the current state of Android smartwatches. They can track steps, control music playback, give you turn-by-turn directions on your wrist, and allow you to respond to messages with your voice or quick-reply taps. But these two models are not unique: The Fossil Group offers an array of more than 300 smartwatches under different fashion brands—including Diesel, Skagen, Tag Heuer, Kate Spade, and Movado—that have essentially the same internal components and software, so you can pick the watch design you like best.