Really tricky. The big invisible (to many people) piece of progress is equalities; homophobia was much more overt back then. But I still think the best time for us in the UK was the 1997-2001 period. "Cool Brittania" to Iraq War.

1990 probably a bit too early. Right at the end of the Cold War. Deindustrialization still a big, ugly scar across many cities. The Troubles still ongoing; few residents of Northern Ireland would set the time machine back before 1998, I think.