What is the significance of Othello's suicide at the end of Shakespeare's Othello, and does it achieve anything?

Considering the Aristotelian definition of a tragic hero,
Othello's suicide is significant because it marks the protagonist's acceptance of
responsibility for his actions and serves as his self-punishment.  Some critics argue
that in taking his own life, Othello actually takes the easy way out.  (He explains,
after he stabs Iago and Iago brags that he won't die as a result of the wound, that in
his view "'tis happiness to die.")  Essentially, these critics think that Othello
doesn't have to suffer the consequences of his actions for very long.  Other critics,
though, argue that Othello's suicide is the ultimate punishment.  If we consider suicide
to be a sin, which was the accepted belief during Shakespeare's time, then we can assume
that Othello will end up in hell for what he has done.  Either way, Othello's suicide is
his form of self-punishment and shows that he has accepted responsibility for his
actions.