where do i begin, outside the pokemon league for its gorgeous music. Route 209, Routes leading up to Snowpoint. Snowpoint City itself.
probably my favourite though is hearthome. sometimes if i just woke up at stupid o clock in the morning and cant sleep, i'd throw on diamond and slowly walk around hearthome taking in the gorgeous night time graphics and music, talking to every NPC for the hell of it and taking a random buneary or smth from the PC box into amity square. 10 minutes later i'd be drowsy, shut the game off and sleep till a sensible morning time.