I have been playing around with an old Pentium 133 laptop and imported my favorites to it. So here’s some MPSIMS I have been thinking about:
My oldest links are from when I converted from Netscape to IE and I imported them–October 27, 1997, three OS’s and several computers later. (And I always swore that I would never use IE)
What are your oldest?
yahoo - since about 1996 i think (when i first got access to the net via a mates, dads computer).
About two weeks.
My primary hard drive died on the 15th and had to be replaced. I had double and triple backups of all my vital files (resume, portfolio, etc.) but had never thought to back up my bookmarks. 
Since this is more of a poll, I’ll move it to In My Humble Opinion for you.
Cajun Man ~ SDMB Moderator
All my link dates got reset to Nov. 2002.
I changed browsers and the Import re-dated them all.
August 8th, 331 BC. I think it was a Tuesday.
Mine is missing.
iWon
eBay
Dogpile
All date back to about '95ish (when I first got my own internet account).
Of course, I could have selective memory, and just think I’ve been using these sites that long.
A little bit of both. iWon came online in 1999 and Dogpile came online in 2001.
Ebay, however, did come online in 1995 which is saying something, because not many major sites that came online in '95 are still around (Yahoo comes to mind but that’s it.)
Altavista, 8 years and counting. I seem to remember having some in Mosaic before it changed into Netscape in '94, but can’t recall for certain if you could bookmark then. I know for a fact my first startpage was sn.no (Schibstednett, Norway’s first ISP). They’re sleeping with the fishes now though, so no use having them bookmarked any longer - someone else has taken over the URL.
Reason I remember sn.no so well… I won a trip for two to Paris in one of Schibstednett’s first publicity stunts, but traded the plane tickets with the woman who was runner-up since I was too busy to go at the time. Got me a special sn.no T-shirt in return. Bartering skills so strong. Heheh. 
I knew 2001 wasn’t right. I’ve been using Dogpile for ages.
I think you’re right about iWon, though, Cisco.
Hmm, Moz didn’t keep any dates when I imported them so I can’t be certain but I’ve kept the same bookmarks list since my senior year in HS, when I first got on the 'net, which would date the oldest to '95. The ones at the top of the unsorted part of the list are Yahoo!, AltaVista, FTP Search v3.5 (absorbed by alltheweb.com and suckified in the process) and the link to my first homepage (now long gone)
This list of bookmarks started life as a Mosiac (may have been an early rev of Netscape that I first bothered with bookmarks) bookmarks file on a Packard Hell 486SX 33mhz box running winders 3.11 and now dwells inside Mozilla 1.3 on a home built 1.4 Ghz Athlon running RedHat Linux.
Fun facts:
I’ve owned this bookmark file longer than I’ve owned any vehical, had any relationship outside my family, lived in the same house, or had a job.
I’ve had The Onion linked since the late '90s, and 3 computers. Diabloii.net and Unknown News for almost as long.
hrh