i really enjoy DXM, tripped on it only about probably 5 or 6 times though in about 2 years. First time was horrible, but the rest were pretty good. The last time I did (this past August I think), was fucking awesome.
But what I would say the worst drug I've done so far would be methylphenidate or whatever (chewed up concerta). Feel good for maybe an hour or two at best, the rest of it is just horseshittty shit ass.
Also, I did some bipolar drug my ex-girlfriend was prescribed to once. I don't know why she was perscribed to it, but she definetly wasn't bi-polar (fucked up doctor I guess). I forget the name of it, but I had like 3 or 4 of them, and I pretty good for about an hour, but then I had like the absolute most shitty fucking feeling ever after that. I did this in like 2nd hour (~9:45), and after lunch, around the beginning of 3rd hour or something (~11:15), I felt like complete shit. I couldn't stay awake, and I felt really anxious. I called home to get picked up, said I wasn't feeling good, and it got worse from there. Waiting for my ride I had this horrible, horrible anxious feeling, like I could not be in any one spot for more than a minute, its hard to describe but it was fucking bullshit. I was able to sleep for maybe two hours, not much more, but then woke up and it persisted the rest of the night, I couldn't do anything about it. Tried to play some playstation, but I couldn't focus on it, and the shit feeling persisted of anxiousness/anxiety. I tried to do homework, couldn't do that either. I told my mother what I had taken and how I felt, and she wasn't mad but she told me that I shouldn't have done it. I ended up taking a couple tylenol PMs and I was able to get to sleep by about 9:30-10:00. Felt a slight feeling like I did in the morning, but overall, I felt alot better.
If I can find out what the drug was I'll edit this post.