Britax Marathon70 Convertible Car Seat. BEST SEAT EVER!!! Kids are comfortable, sit up high so they can see out the window, also at a good angle in the car so their heads don't fall forward when sleeping. No-fuss straps and buckles. Can purchase clip-on cupholder as well. I use this from about age 1 (does rearfacing as well as frontfacing) to 3 years (or older, depends on their weight/height).
Britax Frontier85. Great for your bigger toddler/kid. Allows you to use 5pt harness for a much longer time than most seats but then it converts to use your car's seatbelt as well. Very well made. Comfortable. No complaints from my boy at all. Love the 2 cupholders and armrests! Fuss free belts and clips as well. Love Britax! I started using this seat for my boy at about 3.5 years old.