Hm... "...a visual novel where a guy enters a new school and has to choose between multiple girls". Darn it... I can't really think of anything that fits this category, except every visual novel ever made...
Nah, just kidding; there are other kinds of VNs too .
All jokes aside, Key's VNs you probably suit you. Personally I believe Little busters and Clannad is something you might enjoy. Hoshizora no Memoria could also be worth having a look at, if you can take it's "loli"-esk nature. Yeah, these are all extremely long, but you don't actually need to finish them to get a decent ending. They work a bit like Katawa Shoujo in that you can stop playing after finishing any one single route and feel like you got a mostly satisfying conclusion. In all of these you would miss out on the unlockable final route if you read like that though, so keep that in mind.
Sharin no Kuni and G senjou no Maou would be pretty good choice too, but they incorporate other elements them just pure slice-of-life romance.
Oh, and welcome to Fuwanovel, a.k.a. best visual novel related forum on the internet!
