Minor nit pick here - mankind didn't make Deep Thought. Deep Thought was made by a race of hyper-intelligent, pan-dimensional beings.
Of course once it found the answer, an even more powerful computer needed to be created to find the question. That computer was designed by Deep Thought and built by the Magratheans and had organic life form part of the intricate matrix for the 10 million year program needed to find the question. Unfortunately, Deep Thought didn't take into account the requirements for the placement of future space byways.
Since I'm thinking Hitchhikers, Marvin and Eddie the Shipboard computer would make great additions to this list.
(along with non Hitchhiker related B.O.B. and V.I.N.Cent from Black Hole, and the droids from Silent Running)