The Hello! Project 10th Anniversary DATA BOOK 2009 was presented to applicants who bought all eight titles as a bonus. Though they were all originally planned to be shipped in early April 2009, significant time was required for editing, so they were sent out in December of the same year.
TV commercials were run for the Mega Best series, but commercials for Abe Natsumi's mega best were also run separately.
- [2008.12.10] Taiyou to Ciscomoon / T&C Bomber Mega Best (太陽とシスコムーン/T&Cボンバー メガベスト)
- [2008.12.10] Hello! Project Shuffle Unit Mega Best (ハロー! プロジェクト スペシャルユニット メガベスト)
- [2008.12.10] Hello! Project Special Unit Mega Best (ハロー!プロジェクト シャッフルユニット メガベスト)
- [2008.12.10] Legend
- [2008.12.10] Tanpopo / Petitmoni Mega Best (タンポポ / プッチモニ メガベスト)
- [2008.12.10] Country Musume Mega Best (カントリー娘。 メガベスト)
- [2008.12.10] MEGA MELON
- [2008.12.10] Abe Natsumi ~Best Selection~ 15 Shoku no Nigaoe Tachi (安倍なつみ 〜Best Selection〜 15色の似顔絵たち)