I like to combine things and see what happens. Anything that makes me feel good is at the top of the list. Using the same drug habitually gets boring, so I like to switch it up now and then. It also depends on the situation... if I have responsibilities and need to get a lot done, I will take some stims. If I wanna chill, I'll smoke some bud and/or take some opiates. If I wanna go out on the town and have fun, I'll eat some acid. If I wanna talk to friends and vibe, I'll take molly. Etc..
Recreationally, I like opioids the best. I can't even put into words how I feel on a decent dose of any opioid. I even enjoy crappy ones like Tramadol and Darvocet. Realistically, my favorite drug class is stimulants, since I am prescribed Adderall as a sort of last resort for treatment resistant depression, and it has helped immensely.