Britax is the best and most easy to use too.I did a lot of research on it before I got mine. The after crash ratings etc is pretty high too. They are more expensive then the american brands but they have been proven to be one of the best out there. Try getting the convertiuble as they will last you a long time. http://www.britaxusa.com/products/Default.aspx
Babiesrus carry them and so does toysrus I think.
I had tried other brands too before, but again this is the only one that has really stuck around. Also a quick tip when u are installing the care seat, take it to your local firestation or police station and get an appointment from them to check the installation.Most of the tikme the car seats are not installed safely enough. They also hold like half yearly carseat safety checks in local areas, or contact the local children;s hospital to get the dates. You’ll be amazed at so many common mistakes that we make.