1987 Cavalier - probably around 1 year or so.
1969 Chevy C10 RCSB 355/Auto/2wd - like 2 months, sat in the garage...
shouldn't have sold it.
1989 Chevy Silverado RCSB 4x4 Z71 - about 1.5 years, 10xxx miles or so
1993 Pontiac Grand Prix - got it with 80xxx or so from my sister, who bought it from the original owners. I got rid of it with 117xxx miles.
2006 Dodge Ram 1500 RCSB 3.7 v6/2wd - got it with 15xxx miles in aug 07, still have it and has 49xxx miles after about 4 years of ownership.