P.S. Romance like School Days Kinda.
Well you won't find a exact match but there are a few very twisted Harem/romance anime's that have come out post school days. These are not must watch animies for the most part just on topic for your second question.
H2O Footprints in the Sand: Expect mach truck sized plot holes and WTF moments but its a rather dark natured harem anime. (please note this is down here because its not a great anime like the other its just got some things in common with school days and is watchable if not messed up)
Shuffle: This one is a very light hearted Harem that has dark undertones. Its not like the "nice boat" ending in school days but its a Harem with a conclusion that I really liked.
Myself Yourself: Another twisted Harem anime this one is fairly close to how screwed up school days was so you might find yourself liking it.
Ef a tale of Memories/Melodies: Very twisted and artistic portrayals of screwed up people getting together and working their way through some serious problems.
Kanon(2006)/Clannad: These I'd consider must watch anime. They are a mix of Comedy and Drama and have significant highs and lows of both. They are both from the same studio and have some similarities but are overall very different and both are well worth watching. Note Kanon has 2 versions you want the 24 episode series from 2006 not the 13 or so episode OVA from 2004.