I got a Garmin Legend for a graduation present from high school (2003) and almost use it exclusively for geocaching. Have done a lot in the San Diego, though doing them on vacations are the best.
So far the most interesting one was a multicache in the outerbanks of North Carolina that took my family to an old cemetry and then to the dunes of Kitty Hawk.
My sister's boyfriend actually did a geocache in Thailand when he was there in February.