Eh, piracetam. Anirecatam or oxiracetam are more expensive, but they're also a better value, because while piracetam is cheap, you're also eating three-plus grams a day of something that tastes like ground-up mothballs. (When the author of the linked article says, "it'll probably have the taste and texture of sugar", you should know they're either blissfully ignorant or pissing themselves laughing. Piracetam tastes like sunshine and gumdrops, totally!) Piracetam and friends may work for you, or they may not, but (as these things go) they're among the most benign nootropics. Either way, they will probably take at least a week of consistent use to have a real effect. (For piracetam, at least, that's often too much trouble, though gelcaps help.) I still wouldn't necessarily recommend them, but odds are you'll just find them boring and move on, neurons intact, albeit with a distinct hatred for orange juice.

Taking choline can make them work better, though for some people, racetams (alone or combined with choline) can cause major headaches. Regularly eating foods with moderate amounts of choline (particularly eggs) is a middle path. YMMV.

While not mentioned in the article, I've had good results with l-theanine, which is mainly present in green tea. (The sort of salty / MSG-ish taste from Japanese matcha and gyokuro is from high concentrations of l-theanine. It's an amino acid, and tastes very umami.) At the very least, it counteracts caffeine jitters, and if you're still reading this, you may already be taking enough caffeine. A bit makes me feel calm-but-alert, though IMHO there's not much point in taking significantly more than occurs in green tea already. I like green tea, but if coffee's more your thing, then powdered l-theanine is quite cheap - it's extracted in bulk from low-grade tea. It's worth a try.

I've also had good results from getting enough sleep and exercising, as lame as that sounds. (I like martial arts, weight training, and bicycling. Find something fun.) There are going to be diminishing returns from nootropics, particularly if you're sleeping or eating poorly to begin with.

Also: Vasopressin / desmopressin is a major antidiuretic hormone, so if you're experimenting with it, keep that in mind.