Disclaimer: I don't encourage drug use for anyone. It has caused me extreme problems over the years.
What that said, of the choices you listed, I chose Ecstasy. One time I took some by myself and went to a busy area and ended up spontaneously talking to some other guys who were walking by, and proceeded to hang out with them. Totally unheard of for me; initiating conversation with random people, period, and then maintaining it without feeling/seeming awkward as hell? It was amazing.
Weed is great for certain things (sleep problems, migraines, etc), but personally it actually has a negative affect in terms of AS-related symptoms. I feel even more unsure of how to communicate with people, even more anxious about doing so, and all of the ways of controlling social inappropriateness that I've carefully taught myself over the years seem to go right out the window. Interestingly enough, actually, in some ways I compare the way I feel going through life with Aspergers to being stoned. The feeling of being in a fog (particularly socially), heightened sensory perception yet less aware of actual surroundings, and at least personally, heightened connection to/ability when it comes to forms of art like music... all mimic being on marijuana.
In terms of speed, I just end up talking too much and rambling on kind of maniacally.
Also, echoing others who say NEVER do coke. It brings out the absolute worst, most evil sides of people.