I am going to upgrade a HTPC, and I was wondering what the least expensive CPU that can handle HD video playback without GPU acceleration is. Currently the system has a 2.6 Ghz socket 478 celeron CPU and 1 Gb ram. The computer needs to be able to handle Netflix Instant Watch, Hulu, Youtube, and other streaming at high resolution, as well as play DVD's (no blu-ray). The socket type of the cpu is irrelevant, as the motherboard will be upgraded as well. As it is now, the computer can handle DVD's okay, netflix with some lag (the sound also is out of sync), YouTube at low resolutions, and Hulu is a slideshow. The choices really come down to a bottom of the line Sempron, a socket 775 celeron dual core, or an embedded platform, such as a dual core Atom. Thanks for any help!