I've been going to Westwood Flower Garden for the last few years, since it moved from its other location in Westwood, and I can honestly say I'll keep going there until I move out of Los Angeles. They offer a great value and their flowers consistently look beautiful. Their staff has always been exceptionally helpful and even remember my name now. Even the times I've left the arrangement up to them, it's come out great. Highly recommended.
Pros: great value, beautiful arrangement, quick service