Not my strongest area, but I'll try to come up with something. There's few that are not very good but what you're looking for, and few that are good but not quite what you're looking for. I also put links to MyAnimeList, so it's easier for you to decide which ones to give a try.
Air TV (you'll definitely like this, one of the best in the area you're looking for)
Clannad (the same makers as Air)
Full Metal Panic! (not quite to my taste except for some of the comedy, but you might like it)
Haibane Renmei (not exactly what you're looking for, but it's good enough to recommend anyways)
K-ON! (all girls high light music club)
Kanon (again by Key, the makers of Air and Clannad)
Kiba (oh, there's no romance or comedy or slice of life or even school life, why do I recommend this, meh, perhaps you'll live it)
Megazone 23 (well there's romance and drama, and it's good too)
Midori no Hibi (this is something even I liked though I'm not a friend of the genre)
NieA_7 (comedy and slice of life)
Ookami to Koushinryou (Spice and Wolf, again not quite what you're looking for, but it's good)
Rurouni Kenshin: Tsuiokuhen (OVA of the tv series, way different and better than the series)
Saikano (Seishuu Heiki Kanojo, ultimate weapon girlfriend (or she), drama, romance, school life)
Suzumiya Haruhi no Yuuutsu (this is everything you're looking for and more)
Tsubasa Chronicle (something a bit different, romance, drama, fantasy adventure)
Winter Garden (well, this is shoujo anime, but you might like it still)
Zero no Tsukaima (never finished it, but you'll probably like it)
