Only the cannabis plant for me, and a handful of times at that. Kind of unfortunate, because my experiences have either been feeling next to nothing or absolutely stoned out of mind and paranoid as fuck. No middle ground, ever.
The last time it was in brownie form. I ate one, felt nothing for an hour, and then said "Fuck it, this shit's not working" and had another.
5 hours later I could still barely move and felt like I could have a heart attack at any moment or die of over-philosophizing. Never again.