I have a 1080p samsung 61' TV. I currently watch movies via mkv files on my PC. They look pretty good but not as good as I would have hoped. I have it connected dvi to hdmi. I am wondering if I got a PS3 and watch BD5 files if it would look even better. I don't want to go out and buy one if its not really going to change the image that much.
It does not make any difference! mkv is a container which is able to store pretty much any video, audio and subtitle format around at whatever bitrate you like. You can remux a whole bluray into a mkv file without having to reencode (so the quality stays exactly the same) if you want to. There is a great remux tool which allows you to turn a mkv file into a format which is playable on ps3 without reencoding (quality stays the same and the process is really quick): http://forum.doom9.org/showthread.php?t=131782