22" monitors are becoming the new cheap screen with 24"-28" being more midrange and 30" being top-teir. If $160-$170 is doable OP then go with a 22" and enjoy the immersion. I've owned two 22"s so far, both of which are on the market right now:
Acer X223Wbd ($160 w/free shipping)
Hanns.G HW-220DPB ($150+shipping)
Shipping for monitors on Newegg for UPS 3-day is about $20, so free shipping does mean something with them. Both have good image quality, but since they are TN panels they don't have quite the image quality of higher end panels.
TN panels are one of three main types of LCD panels and are the cheapest to make/very responsive, but doesn't have the image quality of the other two types: PVA or IPS.
PVA panels are more expensive and mostly found with HDTV's, they have better image quality but generally poor response times (which isn't good for gaming).
IPS panels have the best image quality and decent response times (generally not as good as TN panels), but are very expensive and typically found in medical monitors, $1000+ monitors, or some upscale HDTVs.
THE BIG POINT TO REMEMBER is that this really becomes an issue when you look into doing professional photography or other applications which require a high degree of color accuracy. It is not like buying a TN will get you some dull picture where an IPS will suddenly make angels sing and candy fall from the sky. Side by side these screens look different, but after some use individually the differences start to fade.
That whole explaination was to head off any concerns you may have about buying some trash product. Although I will say the Acer screen has a noticably wobblier base than the Hanns.G as while typing this the screen would shake occasionally. There are no earthquakes going around me either lol.