Before discovering I-doses, if I wanted to have a pretty fun night, I'd mix in my drug effects.
Start off with smoking some hash, drink some bourbon on the side, and through in an upper like a couple energy drinks or a line of coke (usually only used the latter if in South America, not really worth snorting the expensive, but horrible quality snow in the States), and I'm in for a pretty fantastic night.
Now, you guys have already come up with the speedball dose. Any other mixtures a possibility?