Luigi Berry along with Mario Punch Soda, Yoshi Apple, and Princess Toadstool Cherry, were released in 1993 by Shasta Cola in association with Nintendo. The sodas were a hit in Japan, but not in the United States, so all sodas were discontinued in 1994.
Luigi Berry was a berry flavored soda, filled with Vitamin C. It is unrecorded what this soda compared to in taste.
Edit* The flavor of the Luigi Berry is very similar in taste to the "blueberry" version of Red Bull. Both are carbonated, berry flavored, and are loaded with vitamins, but have a very unique flavor profile that is extremely close to each other.