Deep Thought on the Day of the Answer, as seen in the 1981 TV series.
The Day on which, after millions of years of waiting, the race of hyperdimensional beings who built the computer Deep Thought received the Answer to Life, the Universe and Everything: 42.
Deep Thought on the Day of the Answer, as seen in the 2005 film.
Shortly thereafter, Deep Thought revealed that in order to find the corresponding Ultimate Question an even more powerful computer, a computer whose mere operational parameters Deep Thought would be unworthy to compute, would have to be built.