Petal and Leaf is my favorite florist. It is quite pricey for a neighborhood florist, but nothing like Winston's or anything and from time to time you can find some great deals.
I have been buying flowers at Petal and Leaf since they opened a few years ago. I am always impressed with their excellent customer service. They offer help, but will never crowd you if you just feel like looking around. The staff is very knowledgeable and even if you go in with a vague idea of what you want, they will make up a gorgeous arrangement in a matter of minutes.
The thing that I love most about Petal and Leaf is that they go the extra mile with presentation. For example, they use nice greens (nicer than your average florist) to dress up bouquets and they always tie a nice fabric ribbon around your purchase. So even if you can't spend a lot on flowers, they are nicely dressed up and your purchase is sure to exude classiness.
Sometimes their selection is a bit thin, but most of the time they have lots of great stuff to choose from: cut flowers and potted plants, old standbys like roses and tulips plus more unusual flowers.