Usually I lurk around the Pokemon League to be honest. I'm an intense battler who loves level grinding, it just gives tremendous satisfaction. Although you don't gain experience from participating in the Battle Frontier, I loved getting prizes and beating hard trainers who gave me a challenge.
I used to hang around in the contest hall but now contests aren't my thing. They just don't have that spark I'm looking for anymore. Fishing is one of my Pokemon hobbies, I love standing around, fishing for beautiful Pokemon.
Ah and the Pokeathlon along with the National Park. On Tuesdays and Saturdays, I'd eagerly participate in the Bug Contest, it didn't matter whether I was a winner or not, at least it was something enjoyable!
The Pokeathlon tested my skills outside battling. Pokemon to me was more than battling and the Pokeathlon showed it. I adored participating in the Speed Course, even though I'd constantly fall over all those silly hurdles D:.