Modern Amusement makes some awesome polos.
Adidas Originals also has some really amazing polos if you can find the slim-fit ones.
perfect for the beach
Not a Polo Shirt by Band of Outsiders makes some really pleasant garments. While pricier than than your standard polo, the fabric woven on sweet japanese looms that make fade resistant form holding shirts. That may be meaningless but I have two both of which have held up to washing and semi-rugged wear. They definately look sharper and wear better than any polo I have owned. The shirts also operate on the assumption that one need not demonstrate their status with a logo - which is nice IMO.
Just for reference, I own a few BoO polos, and I tried on the new F/W 2010 polo's at Barney's yesterday. Sizing seems to have changed a bit. A size 1 fit me perfect for S/S 2010, but it seems the size 1 has slimmed down and a 2 is more like a 1 from S/S now.
