There's a review of Which's Best buys in the magazine this month, and they've listed the two top scoring Best Buys, plus the lowest priced Best Buy for each group.
Group 0+ (Newborn to 13kg)
Maxi Cosi Cabriofix with Easyfix base - 82%, £200
Britax CosyTot Premium (Isofix) - 81% £195
Hauck ZeroPlus -71% £70
Group 1 (9kg to 18kg)
Maxi Cosi Prioifix - 75% £240
Kiddy Infinity Pro - 78% £130
Chicco Key1 Isofix - 71% £170 (Not the non-Isofix version)
Group 2/3 (15kg - 36 kg)
Britax Evolva 2/3 Isofit - 77% £120
MaxiCosi Rodi XR - 75% £80
Concord Lift Evo PT - 72% £68
They also have a Best Buy in a new category - a lie-flat carry cot - the Britax Baby Safe Sleeper,(77%, £170) designed for babies from newborn to 10kg, lying down