1. Bowser's Kingdom
Awesome music and aesthetic, plus those beak-stabbing enemies were my favourite capture-able characters in the game
2. Lost Kingdom
Loved the ambience and the caterpillars were my second fav capture-able enemy
3. Sand Kingdom
Similar reasons to OP, plus the contrasting juxtaposition of a frozen desert was cool. (Har har)
4. Cascade Kingdom
Superb music, the T-Rex's debut, and just the great sense of being the first step in an epic adventure.
5. Wooded Kingdom
Loved the Uproots, the boss, and the robot watering cans.