has a lot of good information on car seat safety, with a lot of certified techs answering questions.
From what I've read, the middle seat is the safest as long as you can get a good installation with your seat, and it is tethered properly, etc. However, you also have to take into consideration your own safety taking the child in and out, and also possible the parent's back health, as I've heard many parents complain that it's really hard on their back to get their child in and out of the middle seat.
If I had a back issue, I would put my child in the back passenger side so they are generally not in the traffic side. However, I have two children, so I put the older one (who is a better listener and more cooperative) on the driver's side and the younger one on the passenger side. I can't get a tight fit with their car seats in the middle seat so I avoid using it.
Oh, and since I read in your siggy that your DD is just one, you might want to look into keep her rear facing if she still fits into the height/weight range for your seat rear facing, as it's been proven that RF is the safest for children at least up until age 2.