I agree with most people here that the worth of a skill is truly dependent on the type of campaign your running, but even if we consider this there are still skills that shine over others.
I'll refer to spot and listen as they are common examples. I can not think of a campaign setting where these are not useful. A combat melee? Use them to find your enemy. Massive roleplaying? Use them to spot people following you, hear secrets you weren't meant to hear, etc. No matter the campaign, spot and listen are very important skills.
Other skills can also be very important given the right setting. For example, climb, jump, and swim. Some campaigns do make them very important. But in standard Dnd (which we have to assume), very basic magical equipment can easily replace these. And also, you have to consider the player's mindset, and even the adventurer's mindset.
He knows from experience that not being to tie a knot can bring certain doom. He also knows that not seeing his opponents can also bring certain doom. He has limited skill points. Well, he thinks, both are important, but my ability to spot has saved me many more times than my ability to use rope. So I'll increase spot.
Finally, there's a certain logic in increasing the cost of certain skills over others. If we want to get "real world" for a second, certain things take much longer to learn then others. If I apply myself, I can learn to tie ropes and such "relatively" easily and quickly. However, learning to attune my eyes and ears to see and hear better can take much longer.
Again, I agree with many that skills are in the eye of the beholder, but I still think when you look at all of the various campaign settings, some skills are superior to others.