Budget Range: $500 - $800 before rebates but would be willing to go a little higher if it meant dramatic improvements.
System Usage from Most to Least Important: HTPC for movie playback, burning and storing backups of my dvd's and blu-rays, and occasional internet surfing/playing youtube videos.
Preferred Website(s) for Parts: newegg, tigerdirect, or e-bay. Not really particular where i purchase from as long as it is reputible and has the best pricing.
Parts Preferences: I'm partial to intel CPU's but am open to AMD as well.
SLI or Crossfire: No
Monitor Resolution: 55" UN55D7000 @ 1080p
Additional Comments: What I want it to be able to do: Copy DVD's and Blu-Ray's for backup purposes, play back HD video without a hitch, do minor internet surfing and play the occasional youtube video. Gaming is not an objective with this HTPC. Also it won't be near a router so it would need a wireless card installed. I would also like it to have expandability within the case so that if I choose to add another hard drive or two in the future for additional space, that wouldn't be an issue. I would also like it to be as close to silent as possible. I was hoping to build someting in the $500-$600 range but would go as high as $800ish if it meant dramatic improvement. I also would like some advice on a good wireless keyboard and mouse combo to control it from the couch with.
You might want to consider AMD's Llano APUs. They will probably get you the cheapest build and a great experience. They're practically an HTPC on a chip. The AMD GPU will do 24 Hz without a hitch (unlike Sandy Bridge). Since your not doing anything CPU intensive, it might be the way to go.
Here is an OCZ Modular PSU, it has more than enough power, is $50 (After Rebate) and because that case is small, will be great because you only have to use the cables you need. With that Antec PSU you will have to find space to put the unused cables.