It depends on what you define as legal. Most research chems I would not consider listing. I'll just check about MXE and 3-meo-pcp
MXE and 3-meo-pcp are unscheduled. The latter would be my favorite, but they are both great! They might fall under the analog laws.
I won't include the tryptamines and phenethylamines - we all know they are grey market.
Peruvian torch cacti grow all over the south central/south west USA and is legal to grow AFAIK. I'll consider it legal, so probably number one
DXM maybe #2 though I may not use it again as long as I can get MXE.
Kratom #2 since I am going to remove DXM from the list from now.
Salvia #3 - that does some very weird shit. I wish it took about 4 or 5 times as long to wear off though.
Amanita Muscaria #4 very nice, dreamy state. Wish I had the type of otherworldly visual trips some folks have
Phenibut #5 Very good for anxiety - sort of like lyrica, but maybe more sedating. Also some similarity to alcohol at higher doses. When you get up to a good level to help well to induce sleep (at least for me) that is about as high as you can go without being tired much of the next day.
This is also good for Post Acute Withdrawal Syndrome associated with using tons of benzos for a long time (I can't figure what else it could have been. I kept feeling symptoms like mild benzo withdrawal that occasionally got worse/fluctuated in intensity and some other hard to describe cognitive, emotional, and weird tactile changes or hallucinations that respond to treatment with benzos or phenibut). I was worried at times from the cognitive changes that I had some kind of brain damage from overdosing or low oxygen levels while in the nut house because I would start feeling really unable to think clearly. I am so glad that all I have to do is use the right GABAergics to stop it. I did not know what was wrong because most of the symptoms were not constant and varied in intensity. This phenibut info may be useful info to some who want to quit benzos as it seems very effective at controlliing both short tern withdrawal and the long term symptoms of abstinence. Also has some of the same properties you might want out of a benzo but be easier to control. I had reduced my benzo dose enough by the time I ended up in the hospital that there was not much of a withdrawal and after the first week without benzos, I felp pretty stable, like I was in withdrawal but it was not going to change any more. Benzo WD is a lot different from opiate withdrawal - over the course of a few hours, it might feel like it almost goes away and then comes back so bad that you are shaking enough that other people think you are having a seizure. Opiate WD is like a long, miserable sickness that doesn't wax and wane so much in intensity and doesn't have as many weird symptoms - miserable, but not as scary.
Another substance called picamilon (a GABA molecule and Niacin molecule attached together hydrolyzed to GABA and niacin in the brain) may be as good or better than phenibut. It is legal and is much more potent.
I'm not particularly sensitive to phenibut though. I gave what I thought was four small doses (4g, but this was volume measurement by the measuring scoop) to a friend for him to try out. I told him to try 1/4 of it maybe 1-2 hours before bed or longer if he wanted to enjoy the high longer and if that did not do much he could use more the next night. He said he followed my instructions and he did not wake up until at least 12 hours after he went to sleep. He did mix with hydrocodone though and he snorted it. I thought I told him to mix it in with water because it tasted bad but I never said don't snort. I should have said not to snort it. For one thing, it hurts like hell (he let me know about that) and from the one time I snorted it it seemed like I was being affected too strongly for the amount I snorted. I know it is at least 2-3 times as potent plugged.
I guess I would rate alcohol as about equal to phenibut, or #5. I mostly like it at around 2-3 servings or 4 at most for the mild-moderate buzz you get and for mixing with benzos, opiates, and whatever other sedatives I might have lying around. Alcohol is more fun probably but phenibut is more useful to me.
Edit:
I wanted to make it clear that 4g was the total amount of phenibut I gave my friend, not 4 4g doses. I am sure you all realized that, but just had to make sure nobody thought I was that dumb.