Samsung UN50H5500AFXZA

Design
The screen is surrounded by thin, quarter-inch black plastic bezels, with a slim chrome accent bar extending from the bottom edge that gives it a sleek look. The accent bar includes a small protrusion at the center containing the Samsung logo.
Peek behind the display and you'll find HDMI, Ethernet, optical audio, component video, analog audio, and IR blaster ports facing directly out. Two USB ports, two additional HDMI ports, and an antenna connector face left. The bottom right corner of the back of the screen holds a control stick that can turn the screen on, change the channel, adjust the volume, and navigate the HDTV's menu options.
Features
The included black plastic remote is Samsung's usual 9-inch wand with backlit rubber keys and a faux brushed aluminum pattern on the front surface. Its button selection is comprehensive, but it's also crowded with different single-purpose buttons you may never actually use. The rectangular, flat buttons aren't easy to identify and press without looking, either. A dedicated, rounded Smart Hub button sits in the middle of the remote and summons the connecte features, which I'll get to below.

The TV can connect to the Internet over Wi-Fi or Ethernet, and uses Samsung's Smart Hub ecosystem. Smart Hub offers most major streaming media services and online apps, including Netflix, M-Go, Pandora, Amazon Instant Video, YouTube, Hulu Plus, HBO Go, Facebook, and Twitter.
Samsung includes its Smart View 2.0 functionality, which lets you stream video content from your TV to your mobile device. Unfortunately, we couldn't get this feature to work with our Samsung Galaxy S5 using the Smart View 2.0 app, as the phone wasn't able to find the UN40H5500AFXZA even with both devices on the same Wi-Fi network. Also, the Smart View 2.0 app wasn't available for our Galaxy Tab S 8.4 at the time of testing, which is an odd incompatibility issue within the Samsung ecosystem. That said, we were able to mirror our Galaxy Tab S's screen directly to the HDTV using Samsung's Quick Connect feature, and could use the Samsung tablet as a remote, too, giving it a similar experience to Apple TV when connected to Apple devices, while freeing up an HDMI port. We were also able to mirror a Nexus 5's screen to the TV using Android's native Cast feature.
See How We Test HDTVs
Performance 
We test HDTVs with a Klein K-10A Colorimeter, SpectraCal's CalMAN 5 software, and DisplayMate test patterns. After basic dark room calibration, we determined that the best settings for the purposes of our testing was Movie picture mode, with Brightness set to 42, Contrast at 98, and the Warm 2 color temperature. The UN40H5500AFXZA showed a decent peak brightness of 220.15 cd/m² and a mediocre 0.06 cd/m² black level in a contrast tunnel test pattern, resulting in an effective 3,669:1 contrast ratio. Not a top result for an HDTV in this price range, especially since the 48-inch TCL 48FS4610R Roku TV$449.99 at Dell pulled off a similar 3,270:1 contrast ratio while costing $200 less, with similarly accurate colors and only slightly inferior black levels.

The chart above shows the UN40H5500AFXZA's measured color levels as dots and the ideal color levels as boxes. White was close to spot-on, leaning slightly towards the warmer side, and blue was also fairly accurate. Greens and reds appeared slightly oversaturated, but not to the extent that colors did on the JVC EM42FTR$299.00 at WalMart, which made colors appear positively neon. The colors aren't perfect, but they're slightly more accurate, by the numbers, than Sharp's LC-48LE551U$447.99 at Dell, and rival TCL's 48FS4610R Roku TV.
I watched The Amazing Spider-Man, which looked very good overall with a sharp, bright picture and well-balanced colors. The black levels are slightly better than TCL's 48FS4610R and revealed decent shadow detail, although in the darkest parts the alley scenes were blotted out. Highlights looked slightly washed out when viewing the HDTV from an angle. The slightly warm whites were evident during The Jesus' bowling scene in The Big Lebowski, preventing the alley's harsh fluorescent lighting from affecting the varied skin tones of any of the characters.
The screen measured an input lag of 45.2 milliseconds in Movie mode, and 49.7 in Dynamic mode, which is an average result. Dedicated gaming monitors can boast measured lag times as low as 8 milliseconds, but they generally tend to be more expensive with significantly smaller screens. Casual gamers shouldn't have any issues with the UN40H5500AFXZA's input lag.
Under normal viewing conditions using our calibrated settings, the UN40H5500AFXZA consumes 77 watts, which is about average for a 40-inch HDTV. For comparison, the 40-inch Sceptre X405BV-FHDR consumes 57 watts under similar conditions. Using the same calibrated settings with Low Energy Saving mode, which provided an acceptable viewing experience with only a slightly dimmer picture, it consumed a mere 49 watts, which is also on par for 40-inch HDTVs with power saving settings enabled. In the Energy Star-certified Standard picture setting, power consumption averaged out to 60 watts.
Conclusion
There's no doubt that Samsung's UN40H5500AFXZA is a quality HDTV, as it offers good color accuracy, and while the black level and contrast ratio aren't stellar, the viewing experience is still very solid. It's when we compare the Samsung's price relative to screen size that it falls a bit short of our full recommendation. You can get a bigger screen for your money with TCL's 48FS4610R Roku TV or Sharp's LC-48LE551U, both of which perform similarly (though the Sharp lacks connected features) and are available with 48-inch screens at similar prices as the 40-inch UN40H5500AFXZA. If you're specifically seeking an HDTV that's closer to the 40-inch range, TCL offers a 40-inch version$349.00 at Amazon of the 48FS4610R Roku TV, and the Sharp line comes in a 39-inch model$297.99 at Dell for considerably less than the Samsung model.