Sam's house is great.
We spent an extended NYE with a group of 6 + baby. This house is the perfect place to hang out and have a good time, but also has pretty good public transport connections to the center. I actually prefer the "real" London of Islington above the touristy part, and at night it is much quieter (good night sleep!).
We spent most time in the very spacious and very-well-equipped kitchen, but also used the very cosy lounge a lot.
If you want to explore London with a small group or large family, but also want some quality time at home, THIS IS THE PLACE!