my pharm use is limited and the ones i know would be my favorite, i haven't had the chance to try :/
my favorite benzo is temazepam. haven't had one in forever but i absolutely love snorting the 30mg yellow caps! clonazepam is a close 2nd. the duration is what gets me.
my favorite amp is ritalin. i've only tried it once and it was like 8 years ago but i remember how much i loved it. vyvanse and adderall are the only other amps i've tried.
my favorite opiate (that i've tried) is hydromorphone. i've only tried it once and it was 4mg that i cut with my black tar to snort. it felt amazing but i wish i could say i'ved tried iv hydromorph... other than that my pharm opiate use is limited to hydrocodone, only 30mg oxycodone once ever and it was by taking six 5mg percs over the span of a few hours so i barely felt it..., snorted morphine sulfate (which i enjoyed), buprenorphine, and tramadol (eh). i tried smoking a fentanyl patch once but did it wrong... so basically my favorite pharm opiate SHOULD be either iv hydromorph, any ROA of oxymorph, iv morphine, a dose of oxy that actually fucks me up, fentanyl, or even methadone, but i have not been lucky enough to try any of these. i am addicted to heroin though...
as for other pharms, i really enjoy soma. only had it a few times but those fucked me up proper! especially combined with opiates or benzos. also, ambien. only tried it twice. 30mg oral was pretty nice and 10mg iv back to back, that was quite an experience.
sorry, i didn't mean to type a whole story lol.