As I have had to replace my everyday t-shirts over the years my tees of choice have become the Lands End "shaped layering" tees. I have scoop-neck, v-neck, crewneck, short-sleeved, long-sleeved, turtleneck, mostly in black, white and gray, but a couple of colors too. Fabrication is 56% cotton/38% rayon modal/6% Lycra® spandex. They are thin but not see-thru. Great for warm weather; easy to layer without bulk when it's chilly. If I need new tees I wait for sales.
Recently while traveling I spilled coffee down the front of my white v-neck. When I took it off about an hour later I grabbed a bar of soap and washed the coffee stain in cold water, gently wrung it out and threw it over the shower rod. A few hours later - dry shirt, no stains. I put it on again the next morning and the few wrinkles smoothed out on their own. Easy care makes it great for travel. They roll up pretty small too.
What's your favorite travel tee?