The hip looks best to me.

Hip, and no interior vaulting. Attic space. Or, a loft.

Sounds like there's a theme! I definitely think some kind of attic space if the roof is going to be that tall.

Hip roof, it looks best and was popular in Victorian times. How tall are your ceilings? If they're nine or over then do a flat ceiling.

The hip but you have many ceiling options for height. Flat would not be my first choice.

And this is why I love Houzz. I don't know if our Historic Zoning Commission will allow us to do something like this because it will modify the original roofline quite a bit (the small hip roof to the right is original to the house), but It's headed in the right direction. Thank you so much!

@dan1888, I agree, I don't think we'll go flat. I think we'll probably do some variant of a hip roof and just have a false vaulted ceiling or something like that?

Another vote for the hip roof.

Okay, hip roof it is by consensus! Any other ideas on how to tie in the two small roofs on the right of the drawing?

It's not clear what the existing roofs looks like on the back of the house.

I'll try and snap better pics tonight. You can see the two small rooflines on one of the photos above--they also appear on all the drawings.

Here are more images of the rooflines

Another hip vote.