It depends on your budget, response time and usage and perference.
some people prefer 1ms because gaming but most monitor 3ms ~5ms is good enough unless you are very fussy.
23~24" monitor for most brand around 180+ ~ 300+ (exclude special clearance/promo)
27" monitor is roughly 300+ ~ 500+
i think recently there are a lot of promo. I saw one quite tempting from sam**** 27" at 50% cheaper than normal price. Not sure if the promo is still available or not.
for movie, i think 27" would be good and non-glossy preferred IMO but like said, it also depend on the distance between your bed/sofa/sitting place with monitor and also what kind of movie you usually download.
if you download those 2560x1440 type then maybe you may want to consider higher-end monitor for better visual otherwise a normal 1920x1080 monitor is good enough. Also depend on your PC graphics, but most can support.
otherwise, get a TV with media player. lol! sky is the limit*, saw an 70" TV.. wider than my sofa. lol!