Go with what you like and fits your budget. I remember Toms Guide doing a special on gaming monitors like this week (24" monitor roundup). Do a search for that to see which brands got the better rating.
Otherwise its your personal preference. I asked the same question a while back and everyone told me to get the Hanns-G 27.5", but I instead got a 32" Vizio and couldn't be happier with it.
They cost the exactly same price here in Brazil, and i´m between them. Same brand, same resolution, never seen a comparison of them, that´s why i´m in doubt. Some say the p2270 is blue-ish and has poor contrast (due to limited brightness maybe), and some say the 2233SW has poor view angles and ghosting.... Help me please !