I did a LOT of research into this. For the Combo Seats, which are the ones that can go rear-facing and then front facing as they get older, according to the NHTSA ratings (National Highway Safety Admin) and previous Mamasource advice, I found these to be the top 3:
1. Recaro Como ($150-$250) - 35 lbs max rear facing, 70 lbs max front facing, 50" height limit
2. Evenflo Triumph Advance ($130-$160)- 35 lbs max rf, 50 lbs max ff, 50" height limit
3. Britax Roundabout ($280-$310) - 33 lbs max rf, 40 lbs max ff, 40" height limit --- Britax Marathon rated high also.
* I actually bought a Recaro Como. I liked it because it was rated slightly safer and cost slightly less than the Britax, but mainly because my daughter seemed most comfortable in it. I found all of these models are carried by either Schneiders on West 25th, or Babies R Us at Union square, so they are just a few blocks from each other. So, you can just bring your baby along and try them all out to see what works best for her...good luck!