Some of my recent smart comebacks

Creep- that dress was not at all looking nice on you
Me- ahem- you are talking about my most favourite dress

Creep who comes to work half an hour after me- if you come after 9 am they will mark half day for you
Me- that was because somedays when I come in the office will be so empty and all the lights switched off in the rooms that I go back thinking it is a holiday. The Security has to call me back to work

Creep who tells us that the company will fall down if you are absent takes leave
Me- Where were you yesterday, the company has started falling, ladies toilet has already fallen (was destroyed for renovation)