[flobosg]

"Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo."

https://en.wikipedia.org/wiki/Buffalo_buffalo_Buffalo_buffal...

I'm not sure if such an example exists in Spanish. The closest one I can come up with is "¿Cómo como? Como como como."

[Izkata]

I think I remember my Spanish teacher showing us a Buffalo-style sentence that was made of a bunch of "cocina", but I can't find it now, so I'm not sure...

[flobosg]

Could have been something like "La cocina cocina cocina en la cocina": The stove cooks cuisine in the kitchen.