For Bunny, who likes grammar and word play.
The title of this post? It's a grammatically correct sentence [1] wouldn't you know.
Also, add punctuation to this sentence to make it correct [2]:
James while John had had had had had had had had had had had a better effect on the teacher
And finally, while not English, here's a poem in a dialect of Chinese [3] that's just as confusing as the “Buffalo buffalo” sentence.
[1] http://en.wikipedia.org/wiki/Buffalo_buffalo_Buffalo_buffalo_buffalo_buffalo_Buffalo_buffalo