We were using a cheap $25 one from dealextreme but that one stopped working. Not looking for anything fancy, as long as it plays real media files and has subtitles support I am happy, we don't have hd tv so even hd support is optional. Somewhere below $50 would be ok, maximum $100. I looked at the wdtv live but that one doesn't seem to support rm/rmvb. Thanks in advance.
This Astone one will do all you want.
My criteria for buying a media player is quite simple. It must have the following support
*MKV
*RMVB
*HDMI
*1080p compatible..
http://www.xpmicro.com.au/cgi-bin/xpmicro/EP-05.html
$48.50 on special.
Media Player : Astone Media Gear EP-05 1080p USB Full HD Media Player Card Reader/HDMI/H.264/MKV/RMVB