It should be legal no doubt. Maybe 18 or 21 to purchase. I still don't understand all the push back on the issue. The tax income for most governments should be seen as beneficial?
Personally I think it should be legalized for both medicinal and recreational purposes. With legalization comes regulation, you can keep it out of the hands of teenagers and get a decent amount of government revenue which I'm sure every government could do with in today's economical climate. When the most dangerous thing about weed is potentially getting caught with it, you know something has to change.