Lots of good choices. If possible stick with an IPS panel and a proper monitor, not a TV. It really depends on how big you want, and what sort of pixel density you prefer.
For max desktop space, many programmers I know are switching to 43" monitors to replace dual monitor setups and get 4K without have to increase scaling. The
LG Electronics 42.5" Screen LED-lit Monitor (43UD79-B) is a good choice - takes HDMI 2.0 and USB-C/TB inputs.
The Dell UP3216Q that Dr. Stealth recommends is another great choice, especially for photoshop.
If you rather have wide, but not so tall, I think the 34" dell 3415W Curved monitor has been on sale lately and the people I know who have it, love it and usually have 2 things open side-by-side.
The 5K monitor is ... nice .. IMHO, but it's not a must-have in my book.
Get the monitor you'll be happiest sitting in front of and using! In the end, only you know what that means.