Best calibration settings are completely dependent on your preference. I may think something looks better than you think it looks. It's completely a preference thing. Now all that said, some people may have played around with your particular TV a bit more and found some settings they like better for whatever reason, and I suspect we might have a few people around here who could give a few recommendations.
Regarding video format, make sure your input is HD, because the TV displays what it gets. Ensure the content is 720p at least, the device you're playing it on is as well, and the connection between the TV and the device is as well. For instance, an A/V cable connections will downgrade the quality to 480i.
Hope that helps!
-- HD Tech
What are the best calibration settings for Samsung pn63c8000? Also, how do I change format from 480i to 720p?