Ah, if you have your heart set on 3D then the LG is an excellent choice. You PSU will also happily handle dual GTX 460s, so with that graphics arrangement you should indeed have the raw power to play modern games smoothly in 3D.
Just to note: the Dell is actually 1680x1050 - so a slightly lower resolution that 1080p and the sam res as the samsung. However it still looks amazing - mainly due to the 8bit E-IPS panel and very impressive responsiveness for an IPS.