both have positive and negative sides. but I think the most effective and easy way is to use online wallet. but the security must be properly guarded.
An online wallet should only contain the minimum amount of bitcoin you need to spend and nothing more, never put there a significant amount of money since there are many ways in which you could lose your coins, besides with an online wallet the issue is that your coins are always online right there for the taking but with an offline wallet that is not a problem anymore.