Tanjiro:
Tanjiro is so thoughtful. He knows exactly what you like and gifts you your favorite things every so often. He's so precious, handing you a package of (f/food) (that he made himself, what a wonderful piece of house-spouse material) with that endearing smile. So precious, that you can't help but give him a hug.
Nezuko:
Usually it turns out that Nezuko accompanied Tanjiro to get some supplies, and perhaps she saw something pretty that she knew you would like. Tanjiro sees what his sister is eyeing and offers to buy it for you, and Nezuko later hands you a cute little wrapped parcel with some sort of hair accessory or jewelry with an even cuter smile. She loves seeing you wear her presents.
Zenitsu:
If Zenitsu gives you something, he's gonna put a lot of thought and planning into it. It's also gonna be really nice, because hey, it's Zenitsu. He'd spoil you absolutely rotten if he had the funds. He loves gifting his girlfriends with nice things, even if they turn out not to be so nice to him in return (and since he knows you love him, he'll be extra happy about it). Usually he'll hand you a pretty little box with a glittering piece of jewelry or something to wear in your off time.
Inosuke:
Inosuke will try to get you something that you like sometimes, but most of the time he gets you simple things he think you'll like, such as some nice wildflowers on the side of the road that remind him of you in some way. Or maybe he'll give you some food he made himself with that proud smile, "Look (y/n), I roasted this whole rabbit!" He knows that you like anything he gives you.
Giyuu:
Giyuu is very thoughtful and observant (see his doomed plan of trying to win Sanemi's friendship with ohagi). He notes down everything he knows you like and sometimes shyly gifts you whatever that is. Food, some piece of clothing you were eyeing in another village while on a mission, whatever it is. He's a little awkward while giving you presents, but your bright smile relaxes him and warms his heart.
Kyojuro:
Kyojuro usually gives you handmade things, sometimes with some assistance from his little brother. He's confident enough in your relationship that he knows you like anything he gives you (especially if Senjuro helped). Watching your face light up when you see the little hairpin that he and Senjuro worked to make just makes his day (and the hugs certainly do too)!
Muichiro:
Muichiro usually sees you eyeing something and secretly gets it for you, only to surprise you with it later. Your genuine shocked happiness makes him smile; he loves seeing that expression on your face when you see the greasy street food he got for you. (Okay, okay, jokes, but seriously, if he sees you drooling at the sight of some tempura, you bet your sweet ass he's buying you tempura.)
Shinobu:
Shinobu likes teasing you when it comes to things you like. All good-naturedly, of course! If she sees you eyeing something like a cute hairpin or talking about your favorite thing, she may poke a little fun at you for it, but in the end she may end up secretly buying it for you and presenting it to you later with a real smile. Joking aside, she really does enjoy seeing you happy.
Gyomei:
Gyomei isn't that materialistic, but if he knows you really like something, it makes him happy to give you that thing and hear your pleased reaction. It doesn't happen often, but when it does, it feels a little extra special just knowing that your gentle giant boyfriend got it for you. (You're totally squealing about it with Mitsuri later.)
Sanemi:
Sanemi, like with many, many things, is a tsundere when it comes to giving you presents. He may jab at you a little bit when telling him about something you like, but when you least expect it, he may hand you a package of that thing with a cute blush on his face and a scowl. He'll pretend not to be that interested in what your reaction is, but if one looks for long enough, they'll see him looking over at you with a soft expression. Sanemi is very soft for you. Only you, though.