There's a difference between animes that I 'like' and anime that I think it's 'great'. For animes that I like, it has a comedy element like School Rumble or FMP Fumoffu. But for great anime, it's the combination: Artwork + Storyline + Concept

Haibane Renmei
AIR
Last Exile

Actually there's more, especially that Studio Ghibli's production.. But they're more like movies (doesn't have episodes)..