People outside of Spain tend to believe that sangria is the drink of choice throughout Spain. It is widely available, but it's for the tourists. Spaniards are drinking gin and tonics, clara con limón (close to a Summer Shandy of beer and a lemon-flavored soda) and tinto de verano, literally, the wine of summer.
Tinto de Verano is sangria without the work (or the brandy). It's simply an equal mixture of red table wine and a gaseosa, some carbonated soda, like seltzer or lemon-lime soda. Serve it over ice, and you're good to go...easy and refreshing.