May be a little late to list but here goes:
1. Decisive Pumpkin - Wonderful looking and sounding to me, perfectly captures how Christmas Town and Halloween town merge, and one of the best abilities in-game to boot
2. Oathkeeper - Maybe a wierd choice for number 2, but I love the look of the weapon and what it symbolizes to Sora and Roxas as well. Also love it because it carried me through my first ever KH1 playthrough as a kid
3. Bond of Flame - A straight up AWESOME looking keyblade that is what makes Final Form Firaga the crusher that it is, not to mention that it's Axel's memento to Sora
4. Hero's Crest - I just LOVE how this keyblade is so intricately designed, and is a very useful keyblade for mid/early game, even post game in some instances
5. Guardian Soul - A true marvel of a keyblade, sounds awesome, and is a literal pun on Auron, since he is a "Guardian Soul"
6. Oblivion - No keyblade emanates darkness like Oblivion, one of the best sounding keyblades, and symbolizes Riku perfectly
7. Two Become One - Simply said, Roxas couldn't have left Sora a better memento, plus it gives you Final Form
8. Rumbling Rose - Though a little on the short side, it captures Beast's Castle and his relationship with the rose well, not to mention when Sora scores a hit with it, the rose petals are a nice touch
9. Kingdom Key - The most nostalgic keyblade ever, and the first keyblade you are ever handed in KH ever. It's also great for early game
10. Ultima Weapon - Though my least favorite looking incarnation of Ultima, it still looks incredible, and it's long reach and ability make it a great combat keyblade