Success often must include a balance of assertive and aggressive behavior. The difference must be in the balance and/or discretion in which an individual's usage of them is displayed or projected.
Assertive behavior, in my opinion, is the preferred display of emotion, since it is generally non aggressive and allows for compromise and resolution. Aggressive behavior on the other hand, generally creates a comparable response and does not allow conflict resolution.
Aggressive behaviors seldom provide environments that lead to "win/win" situations. Aggressiveness allows you to state your opinion, but does not allow for additional or diverse opinions to be expressed.
Assertive behavior allows you to voice your opinion and welcome other opinions.
