I'd be stuck between Nanny and in home daycare. We've done traditional daycare and hated it - like a pp mentioned its their way or the highway. I couldn't even get them to give my dd water. They insisted since she was under 12mos (11.5mos) either I had to provide them with breastmilk (I was drying up and not responding to my pump and my dd had weaned herself to morning and evenings) or they would give her formula, which she refused to drink. I even got a doctors note and they still wouldn't give her water!
But traditional daycare is also you get what you pay for. We couldn't afford an expensive one and I think a facility that didn't have to adhere to strict federal dietary guidelines for each child so they could get federal money for food would have been willing to work with us.
In home was dandy and more flexible but if our sitter's daughter got really sick, not only did we have to stay home with our healthy daughter, but she would get sick the next day and we would have to stay home again. But with one kid it was good because the girls were close in age and became really good friends.
Now that we have two I would use a nanny. I'd already be looking at $400+ a week so why not? I would want him or her to take the kids out every day though, participate in playgroups, etc.