Monitors with IPS panels are generally the best ones to get, especially when they are paired with a high refresh rate. Right now you can get one of LG's IPS 144Hz monitors for just $249.00 on Amazon, a $101 reduction from the usual price.
The LG 27GL650F-B (great name, I know) is a 27-inch 1080p monitor, with FreeSync support up to 144Hz. The display isn't on Nvidia's list of officially-supported G-Sync compatible monitors, and I wasn't able to find any reports of people manually enabling G-Sync mode, so you should only buy this if you have an AMD graphics card.
You can grab the monitor from the link below. The sale ends at midnight tomorrow (July 16th), and it's exclusive to Prime members.
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