This beverage was discovered at a recent work event, when we had a partial bottle of raspberry vodka, and needed a mixer. That cocktail was about 1/3 vodka, 2/3 lemon-lime soda, with a squeeze of lime. Surprisingly refreshing. (I'm sure it'd knock you on your ass if you drank them like I wanted to.)
The above illustration is for a permutation that I've been in love with for ages. It really is refreshing, since the alcohol content is negligible. That's a pint glass with a shot of raspberry liqueur (any will do, but use Chambord if you're feeling fancy), filled with lemon-lime soda. The liqueur gives a light raspberry flavor to the soda, without giving it any boozy kick. I don't usually bother with the lime.
Want a boozy kick? Add a shot of vodka.