Bought my 2005 Sunfire coupe about 8 months ago. It is a base model, except for a power sunroof and aluminum wheels. Not a single problem with it yet. The best part is definitely the engine, which is both very good on gas, and fairly fast. It's no Corvette, but it will outaccelerate Civics, Corollas, and the like. The engine is also extremely quiet and smooth. You can't even hear it at a red light. But as with any car, be sure to keep it under 2500 rpm until the temperature needle is in the normal range if you want it to last long.
I do have a few complaints tho:
First, the wipers have only 3 speeds: lo, hi, and delay. I can't believe a car built in 2005 still doesn't have fully intermittent wipers.
Second, there is no way to adjust the passenger side mirror from the inside.
Third, the interior quality is pretty low, with various squeeks and rattles coming from the dash, and the car isn't even a year old. The interior plastic also looks pretty cheap, and the sun visor hits the rearview mirror when you fold it down. But I guess a low quality interior is something you should expect in a car that costs only $13,000 brand new.