Reasonable on 23 March 2008
Having played around I'd say:
a) PS3 is better media centre if you're storing the media on it, but is slightly weaker than 360 (only slightly) if you want to stream from a PC or other media server
b) PS3 offers slightly better quality for media playback (depending on source) than 360
c) PS3 has BR and DVD playback while 360 only has DVD
Depending on what you want though you might want to check Ebay for Xbox's modded as media centres with large HDD - I suspect that option still outshines all else - assuming you don't want BR player as well in which case it kind of has to be the PS3.
Try to be reasonable... its easier than you think...
