Dell’s got gamers on a budget in mind with a pair of affordable Freesync monitors: the S2419HGF and S2719DGF.
The S2419HGF is a 24-inch 1080p unit with 40-144 Hz VRR range, while the S2719DGF is a 27-inch 1440p QHD display able to go slightly faster at 155 Hz when overclocked. Both have 1ms GTG response time, flicker-free LED backlights for ergonomics, sRGB colour space, and are standard dynamic range (SDR) via 8-bit TN panels.
Dell provides a standard VESA mount, 90 degree rotation mode, and two HDMI inputs — one HDMI 1.4 and one HDMI 2.0 / HDCP 2.2, so you can run an Xbox One at 120 Hz on them, presumably — as well as the usual DP 1.2 port which is more than enough to handle these resolution and refresh rates.
The TN panels used here are apparently quite good, even comparable to IPS, which, combined with the fact that the 27-inch model is reasonably priced, makes it a good value.