Probably, the maid cafe with the best classical maid outfit: Cafe Cicaro. Unfortunately, you only get to see them once a while. Why? It is a nonregular maid cafe event, and when it opens next is up to how three sisters of Cicaro feel like :-p
This time, Ai, the youngest of the three, decided to open a tea party for everyone. Quite chaotic but fan party it was.... her charm seems to have attracted many people to this small party. She was innocent yet bizarre as usual. When I was there, she said her oldest sister's era was over, and was ripping apart a picture of her sister that she drew. X-(
This cafe first appeared as an event in one of the university festivals in Tokyo. I heard the dress was made by the students in clothing studies. I love the dress of this cafe... probably my most favorite classical maid outfit in Japan now! After the festival, they opened the cafe twice in Akihabara rental cafe, Cafe Triomphe. This time, they opened the cafe in Cafe Favorite Piece, a new concept cafe in Akihabara.
If you want to go to this special maid cafe, you should keep your eyes on their blog, or their twitter account. While it is up to your luck if you get to come across their next event, I highly recommend this cafe for English-speakers. When I went there before with my friend from US, he said Ai was speaking very fluent English. You probably will have no problem there even if you cannot speak Japanese ;-)