def. a big fat blunt. effiecient, disposable, wide variety of flavors, and if you roll a good one like a dutch, and do it right, burns slow as fuck, and you can get like 6 bowls into one blunt.
you waste more in blunts/joints cuz they are lit all the time and keep on burning and smoking and wasting thc but it doesn't matter you're getting high from it. most efficient is definitely a vaporizer, who disagrees is wrong, it has been proven it's better. i like my joints best, a bong is so unhandy, it takes too much time for me, i'm a anxious little bastard when it comes to smoking my daily amount. blunts taste and smoke great, but i don't like to throw in all my stash that many times a day. btw, it fucks up my throat so much more than any other way of smoking, so i smoke them occasionally, more fun for me that way. joints are the way to go
there is a reason my friends and i use our glass pipes about 5 times as much as the other pieces, but the gravity bong produces the hardest hitting high. a pipe is the most social though.