Not romance, but very fluffy and wholesome:
-Bernie no Enikki
-My Roommate is a Cat
-Hakumei and Mikochi
-Binbou Shimai Monogatari
-How to Keep a Mummy (Mii-kun is criminally cute)
-Me and my Ainia (you will cry!)
Romance:
-Tsurutsuru to Zarazara no Aida
-Otoyomegatari (especially when Amira and Karluk are the focus)
-Mimi wo Sumaseba
-Hinomaru Zumou (I know it's not shoujo and it's not cute and fluffy, but the romance between the MC and the girl is the most human, most realistic relationship I've ever read)
-Wish
-Kimi Ni Todoke
-Aozora Yell!
-Bitter Virgin (seinen, but I reread it very often)
-Faster Than A Kiss
-Gokinjo Monogatari
-Kingyou Sou
-Koko Ni Iru Yo!
-Shiroi Kumo
-Tokage Ouji (the main dude is hilarious)
Those are the ones I can remember made me feel warm and fluffy.