I'm also starting to look for a media player. This is mainly to hook up to a CRT TV (and in future probably to plasma or other HD TV). My criteria would be:

1. Able to play wide variety of formats, mainly avi, mkv, rmvb, etc.
2. Must have composite and hdmi output, even better if got component output
3. LAN connection is preferable so I can copy files to it from my PC (in another room)
4. Able to support 1 HDD internally (2.5" or 3.5" size)
5. With USB port for external HDD or thumbdrive
6. Good firmware update and support

So far I think Xtreamer fits the criteria. Any others to recommend?