I may be biased working there, but I really like Banana Republics new polos. They have a gazillion different versions in plain ones....different colors as well as blends like silk linen, cotton linen, etc. and in the Heritage line, they have little elephant logo ones. The prices are cheap compared to those other ones, too.
I also like Boss by Hugo Boss (orange label), Zegna Sport, and Burberry polos for men.