Generation X by Coupland of course. Most any of his books, actually.
Less Than Zero by Brett Easton Ellis
Fight Club by Chuck Palahniuk
"e" by Matt Beaumont to me always felt decidedly gen x. The whole thing is written in the form of emails between different office/cubicle workers in a multinational marketing company. Just really feels like something right out of our generation's Dilbert-esque, Office Space workaday reality.
Early 2000's era book told through email exchanges at a global ad agency. I laughed a lot at this one.
You should check out "e: a novel," by Matt Beaumont. The whole book consists of emails written by the employees of a fictitious British ad agency. It's hilarious.
https://www.amazon.com/dp/0452281881/ref=cm_sw_r_cp_awdb_aqrZzb8FDKN39