Which monitor

I currently have a 60Hz TN Acer H235H, which is a great monitor, but so much more is possible.

I can't make up my mind whether to choose for a 27" 2560x1440 or a (~23) 120Hz display.
To power the screen I am using a GTX670 windforce 2Gb.
I will use it to play games like League of legends, GW2, Skyrim etc.
My budget is about 600 EUR, and I absolutely don't want a glossy screen.
Which monitor would you recommend me?

Thanks for the help

I think the bigger is the better, so choose the 27" 2560x1440, the games will look fabulous on these size.

Choose 27" 2560x1440...it will be best.

Choose 27" 2560x1440, and if possible go for Samsung or hp monitors.

Choose only the highest resolution for the best performance. This is very important for your comfort.

Just to add more support to the comments given, a 27" display with high resolution (2560x1440) would be a good buy and you will get a good brand in your suggested price range.