Well for starters what type of GPU do you have? Like Tuna said, what type of connector are you looking for: HDM, DVI, DP, or *gasp* VGA? Do you prefer TN panels or IPS? I'm personally a huge fan of IPS and can't stand using TN panels. What size do you want? For a 1080p monitor anything above 24inches (the sweat spot for 1080p monitors imo) starts to look stretched.
For 200 USD you aren't going to probably get a monitor with 1440p, 144hz, or under 3ms response time (unless you can find a crazy good deal) so you'll be looking at something with 1080p, 60hz, and 4-5ms. (anything w/ under 5ms response time isn't really worth it for gaming).
This is the
monitor I currently have (saving to get an ASUS ROG PG279Q) and it'd say it's pretty good. Only complaint I have is stock colour calibration is meh out of the box. Acer doesn't calibrate their non-gaming/2k/4k monitors before they ship them like Dell does. If you can calibrate a monitor (not very hard tbh) or aren't really big on colour reproduction then this isn't an issue.
If you want a under 200 USD monitor with 1080p, 60hz, IPS monitor, and under 5ms response time I'd recommend it.
Also side note for picking a monitor brand:
Dell makes amazing (and expensive!) monitors with great colour reproduction but they have horrible response time most of the time and I wouldnt really use them for gaming.
Acer makes great mid-range, IPS, and 4k/ultrawide monitors their quality though is a little meh compared to other manufactures.
ASUS makes the best TN Panels (lacking in good monitors in the IPS area though) and they have a lot of high quality monitors for all price and size ranges.
BenQ makes great monitors (their 1440p monitors are amazing) but can range on the pricey side.
LG is pretty alright imo, they make pretty good IPS monitors with alright colour reproduction out of the box. They don't make a lot of "gaming" monitors though with high response time / hz. Their 4k monitors are amazingly pretty though.