I have two:
1. My "dumb blonde" t-shirt.
Years (& years ago), my sister bought me a white t-shirt. There's a cartoon stick-figure drawing of a woman w/ blonde hair on it, & it says, "Naturally blonde. Please speak slowly."
It's soooo comfortable & is longer & roomy. It's now almost threadbare & there's a little bitty hole on the shoulder. But, whenever I want to feel cozy at night, I'll put it on w/ a pair of flannel PJs. It's like the t-shirt version of "comfort food". It's my "mac & cheese" shirt. Every time we go on a trip, the shirt goes w/ me in my suitcase. I may never wear it while we're away, but my shirt is w/ me.
2. My Lilly Pulitzer top.
It's one of those awesome, bright, happy Lilly Pullitzer prints - royal blue w/ bright pink octopi, & it's a summer top (my favorite season). It has a ruffled neckline & can be worn off-shoulder, & it fits perfectly. I just feel good in it, &, even though it's my absolute favorite top, I try not to wear it all the time. LOL!