I thought I'd share my recent build in case others were researching similar parts.
If you are thinking of a new HTPC build then I'd highly recommend you read this guide in the AVS Forums first. It saved me a lot of time and frustration.
Here is my build:
CPU: Intel Core i3-2100
Motherboard: Asus P8Z68-M PRO
RAM: Kingston HyperX, 2x2GB, DDR3-1600
Hard Drive: Crucial M4 64GB Solid State Drive
PSU: Seasonic X-Series 400W (Fanless)
Case: Silverstone Grandia GD04
Optical Drive: LiteOn iHES212 Blu-Ray Drive
CPU Cooler: Scythe BIG Shuriken 2 (Rev.B)
Case Fans: 3 x Scythe Slip Stream Case Fan 120mm 800rpm
OS: Windows 7 64-Bit with Mediabrowser
Blu-Ray Software: TotalMedia Theatre 5
I'm running a NAS which is why I don't have any storage drives in this build and also didn't need a TV tuner card.
For a remote I'm using this app on my iPhone: Mediamote
I also use this app for Wake on LAN: NetAwake
I've had it up and running for about a month now and it's running like a dream. I was originally thinking of using an i5 CPU but am so glad I listened to reason and went with the i3 as it has more than enough grunt for a HTPC.