Before you buy
You should know that Thunderbolt 2 and DisplayPort 1.2 supports up to max 3840×2160 at 60HZ. But it only covers Retina display up to 20" and non-Retina resolutions up to about 40-inch. 2016 model, MacBook Pros, can run 27-inch Retina displays because of Thunderbolt 3.
Apple designed MacOS differently. It created for people's comfort in mind and pixel density of about 110 PPI for non-Retina, and about 220 PPI for Retina. Which means, other than 110PPI or 220PPI there will be scaling issues like text larger or smaller. However, there's a workaround to fix it, but it results in higher memory usage and GPU work leading to shorter battery life and also blurry pixels which we assume you don't want it. So we added the PPI in each of monitor so you can avoid it if you don't want and added a PPI calculator at the end so you can check your display is compatible with the requirements or not.
If you are looking for a 5k monitor on the market that can compete with the 27 inch 5K retina display, then you should consider these two. In our research, these two are the only ones that can rival 5K iMac (217.6 PPI). Dell UP271K (217.6 PPI) and LG Ultrafine 5K Display(217.6 PPI). However, these are not fully compatible with all Mac platforms. See this Abnormal behavior on some Mac platforms with Dell 5k.
The LG UltraFine 5K Display supported Mac computers (Thunderbolt 3) are
( MacBook Pro (15-inch, Late 2016)
(MacBook Pro (13-inch, Late 2016, Four Thunderbolt 3 Ports)
(MacBook Pro (13-inch, Late 2016, Two Thunderbolt 3 Ports)
You can use 4K displays with these Mac platforms
MacBook Pro (Retina, Late 2013) and later
Mac Pro (Late 2013)
iMac (27-inch, Late 2013) and later
Mac mini (Late 2014)
MacBook Air (Early 2015)
MacBook (Retina, 12-inch, Early 2015) and later
If you are going to get the LG UltraFine 4K Display then supported Mac computers are ( DisplayPort Alt-Mode over USB-C)
MacBook Pro (15-inch, Late 2016)
MacBook Pro (13-inch, Late 2016, Four Thunderbolt 3 Ports)
MacBook Pro (13-inch, Late 2016, Two Thunderbolt 3 Ports)
MacBook (Retina, 12-inch, Early 2015) and later
sRBG and Wide Color Gamut
If you only need sRGB, buy an sRGB only display. WCG means Adobe RGB, Display P3, and DCI-P3 color spaces supported.Incorrectly set up, a wide gamut display may result in over-saturated colors.
LG 38UC99 (110.9 PPI)
If you are looking for a large monitor with all the latest tech this one has it all. Price is still on the higher side but can't complain because its indeed worth its gold especially for digital artists.
LG 32UD99 (137.68 PPI) (HDR)
LG 32UD99 is a new 32-inch IPS display. What makes more interesting this unit is the HDR10 support and 4K Ultra HD resolution.In addition to HDR, the 32UD99 covers over 95% of the DCI-P3 color gamut as well. The brightness may not be the best what we see on HDR TV, but it does pass other 4K and HDR checks as well. It can connect to the new MacBook Pro or 12-inch MacBook as well.
LG 34UC98-W (109.68 PPI)
34UC98 is 34" Curved QHD IPS Monitor with 21:9 aspect ratio. It does have two Thunderbolt 2.0 and supports USB 3.0 Quick Charge. The stand is height/tilt adjustable.It does support screen Split 2.0 (with PIP Mode) and sRGB Over 99% making it suitable for photographers, graphic designers or anyone looking for highly accurate color. It does have a game mode as well. But if you are connecting PS4 Pro into it then the image will get downscaled.
Dell UltraSharp U2715H (108.79 PPI)
Dell Ultrasharp is famous among professionals. New refreshed models does have added features as well. It boasts a 27" QHD resolution 16:9 aspect ratio with an ultra-thin bezel. One best feature is fully adjustable stand. Features like tilt, swivel, height adjust including pivoting both 90 Degree clockwise or counter-clockwise. So it allows the thinnest possible edges to be placed side by side if you are using with multiple monitors.It's easy to set up. The only downside is the price. It's still pricey. A little bit more money could get you a 4k monitor. It won't support PS4 Pro as the image will get downscaled on a QHD screen
ASUS MX27AQ (108.79 PPI)
It boasts a 27" WQHD 2560x1440 IPS display with a frameless panel design which looks aesthetically nicet. The connectivity includes HDMI and Display Port as well.
We go through more than 30+ displays. All screens can't be described here. However, here are other displays which come close to the requirement. These are also good non-retina displays for MacBook.
30- 34 Inch
Acer Predator X34(109.68 PPI)
Dell U3415W(109.68 PPI)
LG34UC97 (109.68 PPI)
Philips BDM3490UC(109.68 PPI)
Samsung S34E790C (109.68 PPI)
25- 29 inch
Dell U2717D(108.79 PPI)
EIZO CS2730(108.79 PPI)
EIZO CS270 (108.79 PPI)
NEC EA 275WMI-BK(108.79 PPI)