I don't think there is an answer to this question, considering the answer depends solely on one's opinion. Also, anime is still being produced so even if there was a best, it could be overtaken by another anime in some years' time.
Besides, I doubt many anime fans can actually pick just ONE favorite series. ;)
cory in the house is the best anime
not the best. but not that worst.
The best selling anime is reported to be One Piece.
Anime's Compilation Best was created on 2009-12-23.
Songebob Mom
NARUTO!
Among the best mystery anime are the tiles Hyouka and Detective Conan.
Some of the best anime pictures can be found on the Anime Paper website or Manga & Anime section of Deviant Art. Some good artwork may also be found on fanpop.
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none of them
"Sword Art Online" is generally well regarded but the 'best' 2013 anime is a matter of opinion .
in my opienin i think dragon ball/z/gt is the best anime manga ever created