Question about settings

[robbing23]

So far I'm loving my IPTV but I have one question. When I have it hooked up to my 52" JVC DLP it looks good(not great but good and I'm happy with it) but when I hook it up to my 50" Panny plasma it looks like absolute crap. I don't know the correct terms to use but it looks almost fake. Are there settings in my tv I should change to help with that? I don't even know if there is something I can change but I figured there might be because it looks so different on the two tvs.

thanks in advance!