Linux will kill your gaming mojo, but if that's not an issue, try lots of distros before you make a decision--don't just go with Ubuntu because that's the one everyone talks about. It's good, but not that great. Personally, I prefer Gentoo.

Avoid Windows Vista like syphilis, though.

Honestly, DVD burners are cheap--make sure you get a good one. Something with dual layer and lightscribe would be best. LG isn't top of the line, but you get good bang for your buck.

Avoid ASUS motherboards. A lot of people say they're great, and they are--when they work. ASUS Quality Control isn't that great, and they ship a lot of factory defectives, so you might have to RMA the motherboard, and that means shipping to and from the United States. The only postal services in the world slower than USPS are Canada Post and the Russian postal service. (Seriously, I live in New Brunswick, and I can get an eBay purchase from Ukraine or Hong Kong faster than I can get something from Maine. Look at a map of the Eastern US/Canada border zone if you don't get it) Personally, I like MSI. Like LG, good bang for your buck.