System Usage from Most to Least Important: HTPC for 55" LCD via HDMI (mostly for local movie and tv files, including 1080p), streaming mlb.tv, pandora, hulu, etc., downloading files with sabnzbd, browsing, music, sharing files over network
Parts Not Required: OS (have Windows 7 license), monitor, keyboard, mouse, tv tuner, wireless card (near router)
Preferred Website(s) for Parts: amazon or newegg
Country of Origin: US
Parts Preferences: None
SLI or Crossfire: no
Monitor Resolution: 1080P TV
Additional Comments: Would like it to be quiet. Like the silverstone case (SECC Grandia Series GD05B micro-ATX). Would prefer to use on-board graphics if it won't be an issue. Are benefits of SSD boot drive worth it at this price? I already have wireless keyboard/mouse combo. Will probably run either XBMC or Boxee as auto-start.
I wouldn't recommend a SSD, especially on a sub-$600 budget.
I'm not too familiar with XBMC or Boxee, so I'm not sure if they're hardware specific in anyway.
I would recommend an AMD build, since your budget is smaller, and you won't really see any difference between AMD and Intel for this usage.
You should be able to get a good deal on an AMD CPU/mobo combo on newegg.
I have the Asus M4A785-M MicroATX motherboard in one of my builds, and it works very well. However, I would recommend it's newer protege, which uses DDR3 instead of DDR2. It's not very expensive, and usually is available as a combo.
For hard drive, consider faster drives like the Samsung F3 for 1TB, and the F4 for 2TB. They are faster than the WD and Seagate drives, and are more reliable on average.
I would probably get a dedicated GPU for a high-res TV. There are GPU charts for HTPC usage floating around on the web and these forums, and I would suggest taking a look at those.
A Roku would take care of the mlb.tv, pandora, hulu, netflix, etc. I have one and it's great, but it just won't handle your filesharing.
Don't go SSD right now. Theres no advantage for the cost. Plus your storage is limited. Just get a fast and big disk drive. If you were concerned about quick boot times, just set your sleep timers and bios for S3 sleep.
When you get to the point of software, I recommend using Windows Media Center 7. Sure it's a little short of features out of the box, but you can use Media Center Studio Software to customize the menu items and display. Also, I recommend using Media Center Browser, for organizing your own video media stuff. It gathers all metadata (posters, summaries, etc) and makes the browser really useful.
However you go, I'm sure you'll have a great time doing it! good luck!
I've seen a lot of reviews recommend the sandy bridge intel processor i3-2100 $130 (http://www.newegg.com/Product/Product.aspx?Item=N82E168...), but I haven't found many recommendations on a micro atx motherboard to go with it. Any recommendations on this? Can I skip the video card by getting the sandy bridge processor?