I really highly recommend the Britax Seats. We have DD now 17 months, in a Britax Boulevard. It rearfaces to 33 lbs and will forward face to 65 lbs. It has a height limit of 49 inches.
When I initially purchased the seat, I fell in love with the cushy depth of the seat. Compared to other seats, this one both appeared and felt a lot more durable and strong. After 3 minor accidents (two of which DD was asleep for and didn't wake up), I can honestly say I have no regrets about this seat. We did end up replacing the seat after the last accident as the car was not driveable and got the exact same seat!
The biggest selling points for me now, outside of Britax's stellar reputation for safety, are the ease that it installs and uninstalls in cars and the fact that the shoulder harness adjusts with a knob - so the seat doesn't need to be uninstalled to adjust and you don't need to guess which harness slot is closest to the best fit for your child, you merely turn the knob and move the harness up or down to get the best fit.
The entire Britax line is well worth the money. It's true that all car seats sold in the US are safe, they are all held to MINIMUM safety standards, but some seat manufacturers, like Britax, design and test their products for higher, more stringent, safety ratings. Right now is one of 2 annual britax sales, so look around and decide quick to take advantage of the deals to be had.
S.