2008 Chevrolet Cobalt SS
Although it was discontinued, the Cobalt SS is one of the best affordable performance cars. Available as a supercharged, turbocharged, or naturally aspirated model, the best SS was the turbocharged 2.0-liter four-cylinder introduced in 2008. The engine delivered 260 HP, astonishing by the standards of the day and more than any of its competitors (via Car and Driver).
Also, the Cobalt SS had big tuning potential and it was easy to get even more power from this engine. Although based on regular Cobalt, the SS version was different from the boring economy car it originated as.