The one thing I was regretful for it was not thinking of my possible future children when buying a carseat. I know it can make things difficult but if you can think of your future needs it may help out now.
I have had a Britax Marathon: purchased when it was one of the top seats on CR.
a Britax Husky: purchased because my son was 40lbs at 2yrs old and I wasn't ready to put him in a belt positioned booster. I picked it because it allowed my son to stay in a 5pt harness until 60.
We were recently looking at car seats as my 3rd child was going to be growing out of her infant seat. We finally decided on the Britax Frontier. We liked that it wasn't as bulky as the Husky and would allow a 5pt harness until 60lbs. The best part was the 10yr warranty so this maybe the last seat we get.
We have always liked the Britax seats we have had and the kids have been comfortable in them too. I can't remember specifics about their safety rating when I bought the Frontier I don't think there were any yet because it was new.
If you want to get some advice from car-seat techs you can post on: http://www.car-seat.org/
Good Luck.
J.