I love Ancient times, especially Greece, Rome, and Egypt, and the Colonial/Revolutionary era in American history. I am very drawn to the Victorian era in both the U.S., England, and Canada, and the American Civil War is a specialty of mine (along with Lincoln scholarship).
The 20th century is a smorgasbord for me! :) Each decade has its own distinctions (and sometimes distinctions-within-distinctions within a decade!). I do find the turn-of-the-century and World War I fascinating, as the last vestiges of Victorian/Edwardian culture start falling away to make way for the 'modern era', and of course I love the 1930s! ;) I do find the '40s, '50s, and '60s of special interest, and the '70s get a bad rap (must be the clothes) but saw so many progressive movements strengthening during that decade (women's lib, gay lib, etc.).
I still love my Internet-available era I'm living in now, but find certain elements of the past to be interesting and sometime superior to the present, and of course find a lot to be improved on now as opposed to the past.
And there's always those sexy fedoras! ;)