Mythago, brought up an intersting point on another blog I frequent, "What exactly is the age range for Generation X?"
I think generation isn't so much a matter of chronological age, as it is a matter of what you cultural touchstones are. What events define your personal recollection and outlook on history.
Even if you do try and set the chronological boundaries, differences in maturity, location and individual upbringing ensure there's always a transitional period between generations of two or three years on either side.
loosely, the baby boomers are the 3 or so generations born between 1945, and 1965, and the gen X'ers span from about 1967-1977, again with that three year transition around the ends
Culturally, Gen X is bounded on one end by Stagflation, the hostage crisis, and Star Wars, and at the other end by the Berlin Wall coming down, the fall of communism, the first Gulf war, and Kurt Cobain Killing himself, with the Reagan years flling out the middle.
Basically if your childhood to early teen years were marked the star wars trilogy, and you were between a teenager and 30 when Kurt ate his 12ga, you are Gen X.
If the earliest music you remember first hand is Yes, Steve Miller, Lynyrd Skynyrd, disco, punk, or new wave, and college radio consisted of REM, Nirvana, Sonic youth, and Smashing pumpkins, you are gen X.
If Clerks, Reality bites, Heathers, and Singles, defined your late teens to mid 20's, you are Gen X.
Actually if your perceptions of pop culture were most strongly started with John Hughes, and most strognly finished with Kevin Smith, you are VERY DEFINITELY gen x.
If you can remember watching every single Brady Bunch episode as a child, you are absolutely Gen X.
This is an unusual one, in that no matter what end of the Gen X age spectrum you fall, the Brady Bunch was a part of your daily life. Although it's original run was only 5 years from 1969 to 1974, the Brady Bunch was repeated so frequently when we were kids, that it is SEARED into our forebrains. When I was a young kid, until I was a teenager (when cable took over viewing habits and UHF TV was taken over by the syndicates) UHF TV was playing the bunch at least four times a day, and often six or eight. No other television show enjoys such pride of place with the Gen Xers, but rounding out the top five come Scooby Doo, the G.I. Joe cartoon, the Smurfs, and anything by Hanna Barberra.
I suppose the real definitive answer however, is political. The boomers were born from Truman to Kennedy, a time of hope and growth, and optimism; The Xers were born from Johnson to Carter, a time of war, misery, malaise, and hopelessness.
No matter what age an Xer is however, their political life is defined by the Reagan Administration. Most Gen Xers weren't old enough to vote for or against Reagan either time, but the Reagan years were so expressly political, they can't help but have laid their stamp on the people who's formative years fell in between the hostage crisis, the fall of communism, and the first gulf war.
Oh, and relating this directly to myself?:
1. The first movie I watched in theaters was Empire strikes back, the first song I remember seeing on MTV was something by the talking heads, the first TV show I can remember is the brady bunch.
2. I was starting Jr. high when Bush 1 was elected, and I was a Jr. in HS when Clinton was elected.
3. My high school and college years neatly encapsulate the cultural end of Gen X, starting with the fall of the wall (I started HS the next year), and ending with the dot coms.
4. I was a college sophmore when Cobain killed himself.
5. I just missed the Gingrich revolution, and the first presidential election I voted in was Clinton vs. Dole (I couldnt bring myself to vote for either, but I did vote).
So I am the very end of Gen X, but I am definitely there. As I said the Gen Xers are most stongly the peoples who were defined by the reagan years from the hostage crisis to the first gulf war. That's me in a nutshell.
UPDATE: Strange coincidence,
Scott Kurtz PVP (one of my favorite comics) goes on a GenX riff today, just as I publish this post.