Thanks guys for all your help. I just want to clear a few things up:
1. I'm not engaged to be married nor am I anywhere close to it. It's just, I'm a long term relationship kinda guy and I date girls with the intention to marry. There is no way I'd get married at only 21 years old (unless it was to Scarlett Johanson).
2. I don't have kids nor do I plan on having kids for at least a few years (I'd have to be married first). Whatever car I get, I will be keeping for at least 5 years. Therefore if I do have any kids during those 5 years, they will still be small enough to fit in the back seat of a sports car.
I've done a bit more research and I'm starting to lean towards the 2010 Genesis Coupe 3.8. It gets good MPG for the type of car it is, it's cheap to maintain, and it only requires regular gas (though if you put in premium it will boost the HP up to 315).
If anyone has a Genesis, please let me know how you like it.