Say "I love you" is one of my favorite romances, as well as Inu X Boku SS. Say "I love you" is a really, really good slice of life and realistic show, and Inu X Boku SS is a great fantasy-infused romance with elements of a ton of genres in an appealing mix. I never understood why Inu X Boku SS didn't get much recognition aside from when it was airing when I discovered it; it's a really quality show with awesome characters and a pretty unique and interesting plot - not to mention the beautiful art style and fantastic music.
On another note, Shugo Chara ended in a really similar manner to Sakurasou by introducing two new characters, and despite there still being material in the manga, it was never continued. Notwithstanding, SC was just as popular at its time, so I can't say whether or not I expect a Sakurasou Season 2. There is still a lot to cover in terms of viewer satisfaction, so here's to hoping for S2.