Steve:
Steve, being a gentlemen, likes to get dressed up in a tux and take you out to a very fancy dinner.
Bucky:
Bucky takes you to a concert for some up and coming artist at a small club in the city.
Pietro:
With how fast Pietro moves pretty much everything he does for you is a surprise, and you love it.
Loki:
Loki makes you dinner, one of the recipes you taught him, and then he performs your song on the piano to show you that he's learning.
Clint:
Clint enjoys cooking your favorite dinners, on the rare nights he has the time to.
Thor:
Thor returns from Asgard early and practically breaks down your door knocking on it, he's excited because he's brought you gifts from Asgard.
Tony:
Tony brings you gifts, like dresses and jewelry, anytime that he's been away for a while.
Natasha:
Natasha likes to bring you gifts from the countries near where she was on a mission.
Wanda:
She brings you flowers at work, a bouquet of deep red and black roses.