K.H.
We used daycare (I liked the socialization and my husband like that there was more than one adult around).
If you go with the nanny route, make sure you list your expectations up front. Some people think nanny=watch and feed kids (no cleaning). Others think nanny=watch, feed kids, clean kitchen, do light housework, laundry, etc. For example, my parents hired a housekeeper/nanny the the tasks were discussed during the interview which included grocery shopping and making dinner for the whole family. Essentially, my Mom needed a wife and that's what they hired. I've heard of stories where the nanny will only watch the kids even through the family *thought* they were hiring a housekeeper. Point being, be clear, give him/her a task list and manage everyone's expectations.
Also, be prepared to them to quit with no notice.
Good luck!