I enjoy tournaments the most, but tend to play better when I gamble on sets.
For the first twenty years I played I avoided leagues, and league players like the plague.
When I first started playing pool there was a large gulf between players(gamblers) and leagues. I would never even think to bring my cues into a bar, and if i played in a bar, it was usually just for beers. The juice just wasn't worth the squeeze.
But since I retired from the military it seems that the two groups tend to overlap much more; no doubt aided by the demise of large pool halls in the US.
Now, I tend to play in the local league whenever I relocate to a new area, mainly just to integrate myself into the local pool scene. Inevitably I can only stomach one, maybe two sessions before I bow out.