The FB group Car Seats for the Littles is a great resource for this question. You can post there with your child's age, height, weight and shirt/onesie size, along with what car you have and what your budget is and they can give recommendations.
Is your baby tall for his/her age? If so, you may want to shy away from another Britax. They have shells much shorter than other seats so if you're looking to rear face past 2 (2 is the minimum for safety), another seat is a better investment. The Graco Size4Me/Headwise/MySize/Fit4Me (same shells with different names at different stores) or the Chicco NextFit are the tallest shells on the market and will last a tall child a long time and a smaller child a VERY long time
Re: Car seat