For me, when I enter someones home, the one thing that leaves an impression, other than the book shelf, is the flowers. I think fresh flowers makes home a home. They so easily elevate my mood when I look at them, I try to keep at least one bouquet of flowers around as well as my potted plants and herb plants in the kitchen.
I also feel like flowers fit in regardless of which interior style you've chosen. A well decorated house always has a theme and I can't think of a single theme where flowers wouldn't look good.
I think it's such a great way to bring a little nature into your living room (or wherever). It's always needed.
My vase is, by the way, a Paul Masson wine bottle. I like this way of recycling!