TOD
My ideal decade is not a calendar one, but a span like 1958-1967.  Or maybe 1957-1966.  In other words, the late 50s / early 60s.  And like TCB, as long as we're making demands of the haineshisway.com time machine, I insist upon being there as my current self, but at an age more like late twenties.  (I was going to say 20s-30s-ish, but why not go for broke.)
Yes, we always look back through our rose-colored glasses, but I nevertheless subscribe to the notion that civilization in general, and the arts and entertainment worlds specifically, were at a peak during the core of those years that I would like to relive with full awareness and appreciation.
But I'll tell you what.  If the haineshisway time machine cannot grant me that, then I will very happily settle for the 1970s.  See what a generous and flexible person I am?