Which of these motherboards is better???

The first one is the best feature-wise. But somewhat of a useless product in the sense it supports the DDR3 low end RAM's. Back in the days on LGA775 DDR3 was pretty new and was not normally used with LGA775 chips. So if you already have a DDR2 RAM's no point going for it.

So that leaves the second one as the best.

If you are planning to buy a new rig to make a media center PC, i would say go for none of these and settle for something else.
 
If you already have DDR2 RAM, go with #3. The G41 chipset is newer than the G31.

If I were building a pure media center/HTPC, as much as I am pro-Intel, I'd get an AMD system. The built-in graphics are good enough to stream HD video.

If not that, I'd get an i3 system.