Mine would be Pokemon Mystery Dungeon: Blue Rescue Team. The story was, in my opinion, better than that of the Explorer titles, and the lack of Friend Areas in those games really sapped a lot of satisfaction out of it for me. Not to mention the inability to recruit everything was highly frustrating. Whilst there were less Pokemon to get in Blue, you could get all of them up to the third generation, and as my first delve into the Mystery Dungeon spinoffs, it just felt more exciting. The graphics were bright and cheery, the OST wasn't half bad, recruiting Celebi was perhaps the hardest thing I've ever had to do in any Pokemon game, and it didn't get boring...although it DID get frustrating sometimes, particularly when it came to recruiting Deoxys and Mew.