A Beautiful Mind

Whether or not you would actually go ahead and do it, there are various reasons people give to clone a human:

To allow an infertile couple to have a child:

The Italian doctor Severino Antinori said in an interview once that he wants to offer cloning as a treatment for infertility. Critics have pointed out that anyone who was a clone of one of their parents would be under unknown psychological pressures throughout their childhood. Would they feel they were living up to the achievements of their 'original'? And how would a woman feel about bringing up a much younger version of the person she fell in love with?
To bring back a child killed in an accident:

In recent years, some bereaved families have contacted scientists asking them to clone a dead child. However, even if human cloning was possible, families might be distraught to discover their new baby was not exactly like their dead older brother or sister - and the 'replacement' child might suffer feelings of inferiority about being born purely to take the place of their dead sibling.
To replicate the talents of exceptional human beings:

If Mother Teresa or Einstein could be genetically reproduced, their clones might choose very different paths in life, and disappoint the people who had chosen to create them.
Out of curiosity or to attempt some sort of immortality :

The scientist Richard Dawkins has expressed the desire to clone himself out of pure curiosity. Immortality through cloning seems an impossible goal because the clone’s experiences and thoughts would be their own, not those of the cloned adult.

I am not mature enough to talk about whether cloning is ethical or not ,although i feel it is good to understand cloning for scientific study but if its for any other reasons like those given above i think original is always better.