I think this question/poll can be divided into what type of noise your hear. As several posters have mentioned: if it's just an odd sound or "bump" in the night that is probably nothing, I take my handgun; but if I'm sure someone's breaking in the house/invading, I take SG/rifle, et. al. Also, it's different for those who may have kids to protect, and those who only have to protect the lives of those in their bedroom.
For me, if it's just that odd bump, I take my Glock 17 w/ attached M3 tac light. However, if it's the noise of breaking glass, or an attempt to batter my front door in, I have to grab the M4 and protect the entry to the stairs that lead upstairs to our children. If I was alone in my room, I would call 911 and bunker down with my M4 and Mossberg 590A1. If you have the budget, making a room that you and/or family members can get to a hardened saferoom, it surely is better than trying to clear your house alone or intervene alone. Like I said, I have to go out of my room; but if I didn't, I'd hunker down after calling 911 on my landline or cell (you should have both on your nightstand because it is easy for a determined burglar/invader to disable your landline). I know some out there want to go protect their property, but in my opinion it's not worth getting shot over; plus, that's what insurance is for.
Finally, I also love my German Sheppard who can patrol inside and out via his doggie door.