You may never see the car seat aisle again after purchasing the Diono RadianRXT. It converts from a rear- to forward-facing seat and later to a booster, and it boasts a full steel frame and aluminum reinforced sides for top-notch safety, along with 12 adjustable height positions. Rear-facing 5 to 45 pounds; forward-facing 20 to 80 pounds; booster up to 120 pounds. ($340)
Perfect if: You like to jet—the travel-friendly seat folds flat.