I've had a lot of amp, MJ, and beer in my days, but still have a low enough tolerance that I really like:
-40mg oral IR dexamphetamine taken all at once, with about 4 beers sipped at over 5 hours or so. Beer can sorta negate some of the euphoria of the dex, but not nearly as much as Xanax or Klonopin, and it adds some of it's own. Really smooth combo and I can control myself okay.
-0.5mg Xanax with a full bowl in the Volcano or a blunt bigger than I'd normally ever smoke myself. Just enough Xanax to keep away the paranoia I sometimes get when I smoke alone. The relaxing qualities of MJ really shine here, but I get less of that slight psychedelia that allows weed to add novelty to music or TV you've seen before.
I've had Dexedrine script for many months at a time and sometimes had as many as 20+ Lortabs around, but I've never got the chance to mix the two. I'd really like to combine my favorite stim with any decent opie (IR oxy, morph, or hydromorph), but considering how I only get good euphoria from opies when lying down, maybe I'm not missing out on too much. It'd take away from one of my favorite parts of Dexedrine, which is getting really into something I'm actually doing, although maybe it'd actually help me stay one-dimensional in pursuit of opioid euphoria.