in richmond, va, there's a tex-mex place (more tex than mex) called Border Chophouse, which has a sunday bloody mary bar, where you get a half a glass of vodka and ice and they let you loose on a huge selection of mixers, hot sauces and veggies/condiments.
it's pretty incredible. my friends and i used to try to come up with the wackiest, yet tastiest shit ever.
tragically, other bar versions are not very good in comparison