I have a bunch of wicking sport performance t-shirts from running road races like 5ks and marathons which I like for commuting. You can usually find the same kind of shirts at Walmart, TJ Maxx, Ross and other bargain places for $5 to $10.

I have a few polo/collared wicking performance shirts too which are nice. I'm relatively thin so most of the golf shirts fit a little too tent-like for my taste tho.