I'm a really big fan of Under Armour base layers during the summer and winter. Their stuff is notorious for becoming really really stinky after just one wear. All of my cycling jersey's get nasty, too, after a long day in the saddle in June.

I got a couple bottles of Win (the sports apparel laundry detergent) and have used that since the fall. It was an immediate difference because it completely removes the smell. So much so that I had worn a pair of winter cycling tights for 3 days straight (7+ hrs!!) and my girlfriend didn't take them to do the laundry. She said she did the sniff test to everything and they apparently didn't smell. The stuff works great and I recommend it.