Toradora, School days, CLANNAD, Kanon, Air, ef a tale of memories/ melodies, B Gata H kei (just finished airing, ending was a bit meh), K-ON! s1 and 2, School Rumble, Maid-sama, i'm going to assume you've seen these but i'll say em anyway, Lucky Star, Azumanga Daioh, Excel Saga, I've heard Ichigo 100% is pretty good. Arakawa Under the bridge is ongoing and it's hilarious. Bakemonogatari is good and the last ep should be soon. Omamori Himari, Working!!, Angel Beats, Baka to test to Shokanju, Hanamaru Youchien. Here as some which are mainly about the fanservice aspect, i don't know if you will like em but the story's are all slice of life/romance/comedy so; Ladies v Butlers, Kissxsis, Love Hina, ( i could put Omamori Himari and B Gata H kei in this section but meh.) And of course;
The melancholy of Haruhi suzumiya.
Higurashi no Naku Koro ni, it has aspects of Slice of life, romance and comedy but that's not nearly the main themes in it.
inb4 the incoming flame.