Go with something you have made before - and you know is good.

Nothing worse that being offered something disgusting by the boss - as you feel obligated to choke it down and exclaim how good it is.

I think something basic is good (as you said chocolate chip), as it appeals to many.

Another idea would be to make chocolate chip bars. For some reason I think they are a little bit nicer than cookies and don't require any additional effort (cutting versus forming). I bake in a 13 x 9 pan with the foil strip method.