Brandy & Diet Coke (I STRONGLY prefer brandy straight up, but this thread is about mixed drinks).
My college roommates came up with an amazing drink that was once my favorite, but I vow to never taste, smell, or even look at it again... Tanqueray & V8 Splash (we preferred the Kiwi-Strawberry kind, but obviously any flavor of V8 splash works). We called it the Taint Lick. One night we drank it out of bowls because all of our cups and glasses were dirty. It's hard to accurately gauge how much alcohol you're pouring into a bowl. That was the last night i ever drank a Taint Lick.