Liquid Cocaine is very nasty, but fairly strong. Then again, if I'm going to drink something that foul-tasting, I'd rather just get a shot of straight liquor. However, I do have friends who love it.
If you're looking for a mixed-type drink to get you fairly messed up, my top three suggestions would be:
-Mind Eraser
-Flaming Dr. Pepper
-Four Horsemen (the four-shot variant, not the one-shot version)
The above list goes in descending order from best- to worst-tasting, and in ascending order from weakest to strongest.
I feel like there are a few I'm forgetting, but I can't think of them at the moment.
Or, as someone else suggested, you could just shoot 151 (or better yet, everclear) all night. You wouldn't have an esophagus by the time you were done, but you'd be very drunk.