I started relatively early this year in geocaching. At first our area was devoid of coins (or so it seemed to me), but as I continued caching I came to find and admire geocoins as movable art. It didn't matter if the artwork on the coin was polished and professional or more amateur in nature.
Currently I enjoy collecting all types of geocoins. I have some of the older non trackables (I especially like the group coins such as the nerds v1, MWGB chicks, etc.) as well as the artistic (Tenwar, Tsun's Earth Turtle) and personal coins (Atlantagal's 777 coin, Gelugon's Cache the Dragon).
The best thing that I like about geocoins is that for the most part every single instance of finding, trading, or buying a geocoin is a meaningful transaction. I enjoy finding and sharing coins in caches as part of getting to know the geocaching community. Trading coins gives me insight into others personalities and likes. Buying is a joy as I usually purchase coins that have some sort of meaning for myself rather than just because it is a rare item.
The new revolution in geocoins is great as it allows for more expression. I still like the older coins but the new coins (spinners, firestarters, hinged, 3D, coin minting advances, etc) I think can come closer to what the designer wanted to share with the world. I generally look for a combination of artwork design, idea behind the coin, and meaning to myself. Some of the popular coins don't appeal to me personally but I can see where others would (Sort of like having a favorite Football team). I really haven't run across a geocoin produced for truly commercial purposes yet even if the current collectible nature of today's geocoins are making them so.
All in all I admire those who delve into their psyche enough to produce a geocoin and hope to join their ranks in the near future.