I would recommend...

We purchased the Britax Marathon car seat because of the overwhelming recommendations from our physician, friends and a car seat clinic I had attended. It may be expensive and at first the price gave us sticker shock, but it really is the safest car seat that is out there.

Our son got in his "big boy" car seat when he was about 6 months when he out grew his carrier. When he was rear facing it was a bit uncomfortable since the amount of space it needs in the back seat. We had to have the seats hiked up quite a bit. Now that he is forward facing, he is very comfortable even with a thick jacket on.

I have friends that their children are still using their Marathon Car Seat and they are nearing 6 or older. So it will last until your child is ready for the booster seat.

I also like the ability to recline the seat a bit, it will allow baby to take a comfortable nap on long car rides.

All in all, I definitely would recommend this car seat. Although, keep in mind that you mind be a little squished in the front seat until you are able to turn the seat around to forward facing!!