One of my favorite summer drinks is Sangria. It's incredibly refreshing on these warm summer nights, and is a great addition to any get together. Even if you don't like red wine, I can almost guarantee you'll like Sangria.
The best part is that it's super easy to make, and you don't have to buy expensive wine. We generally use Trader Joes Charles Shaw. You know, 2 Buck Chuck :)
If you'd like to serve right away, use chilled red wine and serve over lots of ice.