Personally, I've seen a few shows that I asked "Is that really the end?" at the last episode of the show. Spiral is one, as is Fooly Cooly. FLCL was only 6 episodes long and I'm pretty sure everyone who saw it wanted more than that. And Spiral's ending was just kinda... blah, like they threw it together in a few minutes -.-
Any of you guys seen animes with less-than-satisfactory endings? ^.^