The folks over at Anandtech have been putting four HTPC systems through their paces. HTPCs are a different breed to regular PCs, or at least they should be, and Anandtech have considered that in their review, which is nice.
By far and large, the biggest change when switching to a home theater PC (HTPC) that has to be made to the computer is the case. Vertical towers (despite all the recent improvements in the looks department) still simply don’t work well aesthetically with other livingroom electronic components.

Luckily, there have been many improvements made in this category since the inception of the HTPC, and as such, we were able to round up four very nice looking enclosures to compare in this article. Every unit is advertised as being able to handle a full ATX motherboard, and since the demands for a powerful HTPC are relatively high, we’ll be giving these cases’ cooling systems a vigorous workout with a brand new 3 gigahertz Pentium 4-based ATX test bed.
[Anandtech]