I'd second Dell for monitors. You can also get a 4K TV, but do your homework on 4:4:4 chroma, since not having this results in basically JPEG compression on the image, which results in things like red pixels around text making it blurry. Note also that the Vizio 2016 P series claims to do 4:4:4 chroma at 60hx at 4K over HDMI, and it connects at that rate, but the actual displayed image is 4:2:2 or 4:2:0 in the low-latency gaming mode. http://www.rtings.com/tv/reviews/by-usage/pc-monitor/best has a good list, but in general, if you want DisplayPort, you won't find it on a TV. There are also things like the Wasabi Mango, Seiki, LeTv, modded freesync firmwares, etc. I just wanted something that worked, and for gaming at 120hz@1080p on a 55" IPS screen, I'm not disappointed.
Going the other direction, the Acer Predator XB321HK is a 32" 16:9 (I'm not a fan of the ultra-wide stuff) 4K screen with great picture and GSync if you play games with Green Team's GPUs. It's over a grand and only does 60hz, but it's a big nice 4K panel and it's not a TV.
Lastly, you have things like the Dell P4317Q, which is targeted at stock traders. It's a 43" 4K screen for a relatively-affordable $1350 with a proper DisplayPort input. I nearly got this instead of my Vizio P55-C1 (which is the only IPS screen of all the 2016 Vizio P series), but I liked that the Vizio did 120hz, but I'm disappointed about the lack of real 4:4:4 chroma and the resultant blurry text. Still, if you want a huge desktop monitor, the Dell might be the way to go. The Philips BDM4350UC is about the same as the Dell, and has a lot of discussion here: https://hardforum.com/threads/philips-bdm4350uc-43-inch-4k-i...
Going the other direction, the Acer Predator XB321HK is a 32" 16:9 (I'm not a fan of the ultra-wide stuff) 4K screen with great picture and GSync if you play games with Green Team's GPUs. It's over a grand and only does 60hz, but it's a big nice 4K panel and it's not a TV.
Lastly, you have things like the Dell P4317Q, which is targeted at stock traders. It's a 43" 4K screen for a relatively-affordable $1350 with a proper DisplayPort input. I nearly got this instead of my Vizio P55-C1 (which is the only IPS screen of all the 2016 Vizio P series), but I liked that the Vizio did 120hz, but I'm disappointed about the lack of real 4:4:4 chroma and the resultant blurry text. Still, if you want a huge desktop monitor, the Dell might be the way to go. The Philips BDM4350UC is about the same as the Dell, and has a lot of discussion here: https://hardforum.com/threads/philips-bdm4350uc-43-inch-4k-i...