Sword is the main weapon in many action anime, and of course, main characters in Japanese anime use them to fight/survive in battles. Each of swords has different power and their owner release great power in fight scenes, I think that the reason many people decided what swords are the top 10.
Let's see top 10 swords in anime that anime fans voted for.
1. Zantotsuken (Lupin III)
2. Excalibur/Caliburn (Fate)
3. Beam Saber (Gundam)
4. Zanpakutou (Bleach)
5. Derflingher (Zero no Tsukaima)
6. Wadou Ichimonji (One Piece)
7. Benisakura (Gintama)
8. Nietononoshana (Shakugan no Shana)
9. Tessaiga (Inuyasha)
10. Reppuugan (Strike Witches)
P.S. Why are Excalibur (if plus with Avalon) the second? What about Nenekirimaru (Nurarihyon), Shishio (Ga-rei) and Christ (Black Cat)?
Source: Sankaku Complex