I can't contribute a lot because most of my year was spent reading the notoriously long White Album 2, the best girl being Touma, of course.
The biggest surprise for me is Mamiya. I already had some expectations for it being called a hidden gem, but I did not expect how much I'd enjoy it. One of the best VNs I've read overall.
Best support character is Sunohara, from Clannad, which I read for the second time.
Aside from WA2, my best girl was Olivia Berry, from Aojashin.