There is a nice deal on Britax today. You can get the Marathon Classic carseat for $150 plus shipping is free from Target! This comes in the Solstice pattern so a great color for either gender.
We have used Britax for both girls and I really think they are some of the best out there as far as car seats go.
A nice feature about the Marathon is that it easily grows with your child and converts from rear facing to front racing. The maximum weight rear facing is 35 pounds and 65 pounds front facing.
This same seat is selling for well over $200 on Amazon so this is a great deal!