Which one to buy Dell is 200$ cheaper than nec & also got more inputs than nec but Dell wont performe as good as nec ,i will use it for multitasking & multimedia(gaming & movie) so pls help me to choose the best i will be using it in my next rig (orderd in amazon) which will be powerd by gtx 480
Go with the Nec, I have one and I have to say it is amazing. It isn't as good as its predecessor 2490wuxi (which had a polarizer that removed the at-an-angle white glow) but it's still your best option. It also depends on what you want. The Dell is S-PVA (deeper blacks, gamma shift) and wide gammut, while the Nec is eH-IPS (poorer blacks, greater color stability) and regular gammut. The Dell is a consumer display while the nec is oriented towards professionals. I believe that it's worth the extra 200 bucks. Here is one detailed review about the Nec http://hardforum.com/showthread.php?t=1447336 (you have to consider that 2490wuxi2 predecessor, the 2490wuxi is still considered to be one of the best monitors, but sadly discontinued). I hope that this (not to organized ) info will help.
I haven't read many reviews of the Nec 2490wuxi2. So I can't say how "inferior" it is to the original 2490WUXi.
However, if you are simply gaming and watching movies, then consider the 26" Planar PX2611w which uses the same H-IPS panel as the now discontimued NEC 2690WUXi. It's pretty good for gaming with less than 8ms of input lag. Out of the box colors aren't too bad, but as with all monitors some tweaking is always necessary to get the best out of it.
I use the Planar PX2611w as a secondary monitor. I also recommended it to a friend who does professional graphics where color accuracy is pretty important; he loves it.
As of 2011 the NEC 2490wuxi2 is the best 24" sRGB monitor out there for less than $1,500. You can NOT go wrong with it. Some people's problem is they like to criticize a Ferrari for a stiff clutch ... it is still a Ferrari... no need to buy a Yugo out of fear/protest.