What period in time? You could never return to your own time either.
Me... I'd either go to the Victorian age, 'cause I'm a steampunk fan, or the Renaissance. I could be like the Yankee in A Connecticut Yankee in King Arthur's Court.
_ You know what I hate? People who take certain films seriously.
I would just go back in time to witness things like Jimi Hendrix playing the Star Spangled Banner at Woodstock or MLK's "I have a dream" speech, but never to intervene cause you can never honestly know what effect your actions in the past will have on the present and future. Time travel geeks know this. Hell, the Simpsons have an episode where Homer turns their toaster into a time machine and goes on to show how his minor accidents in the past gave way to drastic changes to his present time.
Yeah I saw that you said I would never be able to return to my time, but that is no excuse to let shortsightedness completely change/ruin the future. I would choose the 90's era to stay in if I couldn't return to my present, cause I feel my knowledge of that era would help to keep me from sticking out or letting me unintentionally alter the future. Plus technology and entertainment was pretty good so I wouldn't get bored and be able to live comfortably, compared to the Victorian era where disease coupled with the sheer lack of medical technological advances resulted in the life expectancy being a lot lower than it is now. The clothes and stuff were alright, but I don't want anything to do with the widespread of VD and the bubonic plague during that era. I'd be perfectly happy with AOL(56k modem and all!), the Monday night wars, and the more widely accepted use of condoms.
If I had to go into the past, I'd want to go back to the very beginning of ancient Sumer (5000 BC), the oldest know civilization or maybe way back to the earliest homo sapien tribes and the "alien" world (with other humanoids) they lived in (250 000 - 100 000 years ago).
The direct future doesn't really intrest me. I'd either want to go far enough so I can experience space travel to other solar systems, maybe even galaxies or crazy far into earths future (say 2 700 000 000 years from now).
I'd go forward in 100 year increments until I find a time I like. I'm a sucker for gadgets and technology so hopefully I'd find a more awesome time period. Hopefully we'll be able to deal with that pesky little problem of aging, so I'd look for a time where they have the means to stop my aging. 80-100 years simply isn't long enough in my opinion, I want at least a few thousand years. These 28 years so far have happened WAAAY to quickly.