My fav was the halo 3 beta... Not sure if that counts but its easily my favorite demo.
Actually scratch that i loved the halo CE demo for PC. That game had a crazy community for several years afterwards. It was awesome
I mostly play RTS and Moba style games now adays as well as ALOT of benchmarking. I do play other games however such as the witcher 3 and Crysis 3, and recently Ashes of the Singularity. I love gaming on the cutting edge and refuse to accept any compromises. Proud member of the Glorious PC Gaming Master Race. Long Live SHIO!!!!