The AMD build has a better all-round processor (4 core), but the Intel is only 35W (against 100W from AMD). If this is an HTPC-only build, the lower TDP is a blessing. You could change the AMD processor for a 3500, which has a 65W TDP, but then you would lose the processing edge over Intel, and wouldn't make much sense.
Thank you so much for the help.
I have ended up with ASUS P8H61-M PRO and your choice of CPU Intel Core i3-2120T Sandy Bridge 2.6GHz LGA 1155.
I didnt understand until now that its the CPU who does most of the work with the 3D and that the Sandy-bridge is in the CPU, not the graphics card.