By far and away, my "funnest" years were at a TWR/APP unit in New Zealand many years ago. They let you loose in a single man/woman TWR at the advanced age of, oh, twenty, and expected you to provide quality ATC to upwards of 150 movements a day on your lonesome. I have so many great war stories/memories ranging from creative uses of bird scaring cartridges and flare pistols to UFO reports from some local farmer to "braking action check" rides in our airport inspection vehicle on frosty mornings. It was non-stop fun and you got to know local pilots well and got lots of rides in all sorts of exotic beasts.
However, as age and bills increase, the logical step is into a centre and you get paid more for taking on the extra responsibility. I'm typing this in the restroom of a Middle Eastern ATC centre but I must say, although the work is still fun and challenging, it doesn't feel as good as my early years in that procedural APP/TWR unit. Sigh!