The perfect compliment to any well-toned body would be a form-fitting t-shirt, or turtleneck in colder weather. The most noticeable and most replaceable would be white, followed by any darker colors, like grey, black, dark brown, navy blue..
Very minimalistic. No huge logos. Get a brand like Calvin Klein or Club Monaco, ..you could save a lot just by buying last season's wear, or from cheaper labels that higher-end brands will usually make to appeal to all types of customers.
Because the shirt will not be showing a huge design across your torso, the stitching, the detailing, and the way it shows off your body better than other brands can and may convey that you're athletic, you have money, but you're not trying hard to impress everyone with it by flashing abstract shirt art all over the place.
If you buy from a better quality brand, craftsmanship will not only be obvious, but you may also notice better elasticity to the fabric, and it will last for many more washes.
However, if you can afford D&G, by all means GO FOR IT! If you seriously think nothing of purchasing a cotton shirt for $200-425, you've got sh*t going for ya!
ps. to all you guys looking for more minimalistic approaches to showing your value, listen to vance9. ex. You have a REALLY NICE wallet..she's not going to notice that until you're paying the bartender, the waitress..or even if she snags it from you and starts snooping around.. as long as you're not wearing it around your neck it might come as an extra surprise, increasing your value once again.
(always keep at least one or more twenty dollar bills in your wallet. Any less is a DLV, and she may just think you don't have the money to support yourself, let-alone, your gambling debts!)