These days you really can't go wrong with one of AMD's APUs. A lot of depends on how much space you want to use up which will determine whether you go mATX, Mini ITX, or ATX and what kind of case. Keep in mind, though, that AMDs new Trinity APUs will be out soon which are going to be a new socket type I believe (FM2?) so it might be worth waiting long enough to get a new chip. I've been thinking about upgrading my HTPC to something like this:
A6-3500 APU $75
ASUS FM1 A75 Motherboard $95
Crucial M4 64GB SSD $90
G.Skill DDR3 1600 8GB $42
Antec 430W Earth Watts PSU $50
Add some hard drives for storage if you want and pick a case that fits in with your home theater. A lot of people really like the nMedia cases for budget systems
nMedia 5000b $50
The A6-3500 triple core APU seems like plenty to me for daily HTPC duties, but you can upgrade to an A8 or downgrade to an A4 if you like. If you want to be able to do some gaming on this also then an A8 would be a better choice.
The A75 motherboards are really the way to go as they have all of the features that you want. Also make sure that you get a motherboard that has HDMI out and S/PDIF out (if you need it) since many of them don't for some reason. I put the ASUS board in there just because I like ASUS a lot.
Silence is key for watching movies so a SSD for the OS is a nice thing to have. Also, I've never actually used more than like 2.5 GB of RAM while watching BluRay movies, listening to music, or even ripping movies but it's so cheap these days no reason to not get 8 GB.
The Antec Earth Watts PSUs seem to be really popular for HTPCs also, 430W should be plenty (the 380 would probably be enough too).
That puts you right around $400 plus the cost of any other hard drives you may need. This should be perfect for watching movies and listening to music.
Oh and I've used one of these in the past
Rosewill Windows Remote and they work fine but these days I am using a Logitech Harmony remote (I still use the IR receiver from the Rosewill though).
Also check out AVSForums for some really great info on HTPCs:
AVSForum HTPC Guide
Anyways that's my opinion but maybe other people feel differently so hopefully you'll get some other possible builds. Good luck!
Edit: I haven't really looked at Mini ITX builds so hopefully someone else can help you out there if you are looking to go smaller. I believe there are some really nice socket 1155 Mini ITX boards (Z77) that might be worth checking out if you want to run a new Ivy Bridge CPU).
Edited by shelter - 4/29/12 at 11:45am
A remote controller is a must, I don't like the idea of using my home theatre with a keyboard and mouse.
). A HTPC would really complete the home theatre system. It would be connected to the AV-receiver with a HDMI cable only since HDMI transfers audio just as well as S/PDIF does.
Also do you need any PVR functions to record OTA, cable, etc?
