You have to compare NOT w/300c (2005 new car) but what's new for 2006.
I think there was the Avalon, Audi A3, Passat, Jetta, BMW 3-series, Charger.
Out of those, the Civic has a good chance of topping those; at least for value and gas mileage and refinement.
Recall, the 2004 MTCOTY was the Prius (if I can remember). So it's not always based on pure HP.