from a stoner POV:
Pros:
Medical (the sheer advantages for medical is huge, it literately is near endless with well over 17,000 medical applications and benefits)(it is also imposable to die of a weed overdose)
bio fuel
paper
industry (paper production, clothing and just about anything that uses cloth or wood as a bonding agent and a item of everyday use far out numbers the uses of wood and wool, as hemp lasts a much longer time and is very useful)
getting high (a truly amazing experience that everyone must try)
crime (when some one is under the effects of weed and ONLY weed all they want to do is lie down, do nothing and talk to friends and maybe eat. unlike on alcohol. also the myth that DUI will increase it totally wrong because i am a driver and all i want to do is lie down with some mates at home and stay the night.)
addictiveness (weed isn't addictive. if the body loses access to weed it go though a FAR lighter process of getting rid of it than on tobacco and alcohol) (take me for example i haven't done weed for 2 weeks now and i feel nothing, apart from a ever so slight temptation to do it. if i was doing this on tobacco after 2 days i would be going crazy desperate for it, but no, i am fine.)
the real differences between weed and tobacco and alcohol:
weed is far less dangerous and less addictive. on weed you want to stay at home with fiends. it NOT cancerous and it is actually healthy for you. It wont cause you to do something stupid and it is a great drug that can really help and improve the world.
Cons:
the smoke and smell of it
the fact it is still illegal.
cost
purity
and yes those are the only real disadvantages of it
now please watch the video as it has worded it far better than I have.