As it's the gaming gadget of this
year '2010' (PS3 Slim was 2009), I think it has to be the Xbox 360 S
It's a great revision, it solves the problems of the previous version: Noise & Reliability, while adding built in Wi-Fi, a larger 250GB hard-drive. a better looking & smaller design and full compatibility with future hardware, all at the same price.
The only contender would be if Nintendo were to release their 3DS before Christmas.