You can't draw the line to a particular vintage for all wines. Like most folks here, my goal is to drink all my wines before I kick the bucket.
Barolo - 2004 Seghesio was the last purchase
Bordeaux - 2005 was the last vintage.
Burgundy - 2005 was the last vintage.
Brunello - I may be buying the '06, depending on reviews
CdP - 2006 Beaucastel and no plans on purchasing anymore
CA Cab - only purchased 2007 Stefania's and no plans to purchase other wines.
CA Pinot - 2007 will be the last purchase.
WA Cab - 2007 QCs