Which SoC to choose?

[nekdo]

I'm buying an Android tablet, and these are the SoC to choose from:
RockChip 2918 1 GHz (Cortex A8, GPU GC800)
TeleChips 8923 1,2GHz (Cortex A5, GPU Mali400)
Allwinner A10 1GHz (Cortex A8, GPU Mali400)

It must play games smoothly, output HD mkv. via HDMI, browsing, ....
Which of these is the best?