I bought a no-name 15" monitor new in 1988. It's on my son's desk now, still working perfectly. Bright and sharp.
I have a Dell branded 17" Trinitron I bought at a thrift store for $20, mfg date 1996 or so, razor sharp, nice and bright (especially since I removed the coating..heh).
I've seen Shinho's go bad in months, and IBM's go bad in 2 years, but that's it. The name brands will generally either fail within a coupla weeks, or they will last a nice long time.