I am currently using a Box Office by Patriot purchased thru CompUSA (TigerDirect) and it supports Linux kernal 2.4.1.0 or above as well as various Windows flavors and Mac 9.0 and above.
The box supports a good number of video formats including MPEG-1 (MPG/MPEG/DAT) up to 1080p, MPEG-2 (MPG/MPEG/VOB/IFO/TS/TP/M2TS) up to 1080p, MPEG-4 (MP4/AVI/MOV) up to 1080p, DivX 3/4/5/6 & Xvid (AVI/MKV) up to 1080p, H.264 * AVC (TS/AVI/MKV/MOV/M2TS) up to 1080p, Real Video 8/9/10 (RM/RMVP) up to 720p, FLV, WMV9 (1080p) and ISO (1080p). Many audio formats including the regulars plus OGG and FLAC. Image formats include JPEG, BMP and PNG.
The box has fast Ethernet, 2x USB 2.0 ports and internal 2.5" SATA HDD connections. (HDD sold seperately, but very easy to install.) A USB wireless adapter is available, but came included in my package. You can stream video from network storage devices.
Best of all, it is small, quiet, has a remote control, HDMI output as well as composite A/V and S/PDI outputs.