During the spring and fall in Phoenix, I'm a huge fan of Olive & Ivy. You can't beat their patio - its first come, first served on huge, comfortable furniture along with fire pits. The areas are nicely divided and its absolutely perfect for large groups. Sometimes the stench of the "waterfront" aka canal can creep up on you, but its usually fine.
What to order? I typically don't get dinner, but like to share small plates like the flatbread with my party. The sangria, margaritas and wine are all really good. Oh - and if they don't just automatially bring it over, but sure to ask for the bread and pesto. Delish!