I have five at the moment... I would have more, but some are pre-pregnancy and this is not the most forgiving wardrobe item.
1. BR shirt with interesting basket-woven texture and tux cuffs. This fits perfectly, but errs on the short side. Mainly used for layering.
2. H&M cotton basic, often for layering, but sometimes on own.
3. Very loose, blousy thin GAP shirt with 3/4 sleeves that roll up and fasten for a shorter sleeve - for the "slim jeans and blousy top" look. Love this in theory and sometimes I just enjoy the casual feel of it (especially with the right bag), but the shirt wrinkles easily which isn't great and I think it should be a bit longer on me.
4. Mexx short sleeved slim-cut empire shirt with tiny side zipper. Very fitted.
5. Woven tunic top of exceedingly thin material, a tiny tad small now and wrinkles too easily. Also getting worn.
On my list: the perfect "man's shirt" - I have my eye on some Gap ones. I love this look and it suits my body. Also, another basic button-down because I wear them so often.
Incidentally, I usually wear these with a vest or sweater over, mainly because that works better with my SAHM lifestyle. They show wrinkles less and get fewer stains, yet look put together.