My own experience is that screens large enough to enjoy movies are too large for gaming. Because I can afford (space and funds) to use different screens for these purposes, I do.
And again, maybe its just me, but I don't understand gaming across three screens separated by two bezels. Further, you're fighting to get higher resolutions to provide better detail, and then you wind up spreading essentially the same picture across 3x the reolution. OK, maybe its cool to show off, but does all that make for better gaming?
Given that my movies and PC use are done (mostly) on separate screens, I find the best choice for me to be a 27" monitor with 1920x1200 (or 1080) resolution. I get as large a screen as I could need for gaming and web browsing etc, and a resolution low enough to easily read text etc.
Just an opinion. YMMV lol.