A lot of folks are using Dell, but their quality has been crap lately and their tested response time is miserable (important if you play games). If you are picky about bleed and conformity, be prepared to exchange a few before you get a good one.
I've been using an LG 27EA83D for several months now. The LG 27EA83D is a wide gamut 2560 x 1440 IPS panel that works better than the Dell for both gaming and photo/video editing. I think Dell and LG use the same glass but it seems LG cherry picks them for their monitor. LG does use PWM dimming, if that bothers you. A great monitor, especially if you grab one when they go on sale for ~$700. I hear the narrow gamut -R version is also very good for a bit less money.