Lets see... Love in a Library by Lilith-dono (complete) end with some nice expectant-father fluff. Then Love in a Library 2 starts with the child of the previous one already born, but its not complete. Also, if you haven't read the first already it's a bit of work getting to the father-fluff.
sesshou_lover's Speaking Without Words has some really good father stuff in it after chapter ten. In A Heart's Strangled Cry by Miss Artemis he's got a whole brood of kids but only one of them is still young. The Broken Miko and it's sequel The Broken House of Taisho by RosieB are a bit like the Love in a Library stories with Kagome becoming pregnant at the end and then the baby being born in the sequel, but his interaction with his kids in the sequel is absolutely adorable!
And in the first he has Rin and then gains another adopted child, not shippou, whom he's pretty fatherly with.
Heh, I could probably go on for ages with these:silly: , but I'll cut it off here. If these don't suit your needs I'll see if I can find something else.
Oh, and if you want a tear jerker, the very end of Zandrelia's Family Honor and then the sequel, Family Reunion, has some amazing father daughter-ness going on, not quite fluffy though...