you indirectly proved that quad is better than dual, even costwiseIf you want some thing for for gaming go for dual core e6850 for the best.( Price & Performance Wise) It's 3 Ghz and has 1333 Mhz fsb. It has 2 cores.
Games are dual core optimized. I don't know of any game that is quad core optimized. You should get it around Rs. 10500-11000.
If you do a lot of multitask go for quad core Q6600. It's a 2.4Ghz beast with 1066 mhz fsb. ( Price & Performance Wise) You should get it around Rs. 9500-10500. It has four cores. ( Price & Performance Wise)
By the way, what is your current config or you're planning to get a new computer.