I think it rather depends which machine, but I can certainly think of some useful things to do with highly sophisticated software that would make me, for one, a bunch happier. For instance, if we finally achieved the End of (Wage) Work, I could, ahahaha, finally get some work done. That is, me and everyone else in the research sector could finally focus on actually accomplishing things rather than scrambling for funding.

And on a more personal note, I could probably spend a while going to practically every nerdy-hobby convention in sight. I could probably get through about three before desperately wanting something serious to do. Of course, then I could spend a lot of time on exercise, or lying around on the beach.