You do need to define your goal for calibration. If it's to make it look "better" to you, you may be disappointed if you've grown up watching, and are used to, out-of-the-box settings (super bright, all picture "enhancements" turned on, etc). If you want it to be as close to the standards as possible, that's another thing. My personal goal is to see that image the same way the colorist saw it on his calibrated display, which was used to make all the decisions regarding how the picture looks. This is separate from the artistic or director's intent issue.