ecstacy would be my second favourite drug after herb, i like it a little bit too much actually, spent tooo many weekends wired up off that stuff, its great because its such and intense long lasting buzz, which is great for raving and clubs. (shame about the evil f*ckin comedown the next day)
acid is a close second but i dont like to do it too often, mainly because of its effects on my sanity and because i find it looses that special spark if its abused.