We have used the 4Ever® Extend2Fit® 4-in-1 Car Seat for both of our kids. This car seat will grow with your kiddos so you won't be having to buy car seat after car seat.
Not a momma but I've been a nanny for years. My current family has Maxi-cosi seats and they look like the most comfortable seats I've seen AND have a one handed latch which comes in real handy when your holding the 11month and getting the 2yr old out!
We have really liked our Graco Extend2Fit as well. It was much more affordable than the one we had for our oldest and my youngest rear faces till over 4 years and has always been comfortable. It is really easy to install as well and not super heavy considering its size.