Best MObo manufacturer for Intel LGA775

Same as for other sockets. Gigabyte, Asus, etc...

I personally liked the 790 ultras from nvidia, with DDR3 support and tri SLI support. Plus they had some really neat tuning utilities from inside the control panel that you could change even the mobo fans and every fan to what ever you wanted to set them at, which works better than speedfan.

If you are replacing a motherboard in an existing computer I strongly reccomend you buy a motherboard with the same chip set as the board you are replacing

G31 , G33, G43
P43 , P45

etc

This will give you the best chance of connecting your hard drive/ windows installation and having it boot