Flat straight stretches of highway are your friends.
The first week with our one-year-old 1992 Cavalier (first newer car my wife & I bought) we bounced off the limiter. It was just over 110 (that's as high as the speedo went). I actually called the dealer the next day and asked, "umm.. is there a limiter on this car?".
My 1999 "stealth-grandma-mode" Buick Century cruised nicely all day long at 100-- again with a 110 or so limiter. Once I got the crazy "pimp my ride" paint I had to be more careful (as I was now
on their radar) but the Z rated tires made it much more solid feeling (not really safe... just the illusion of safety).
My latest is a 08 Silverado, limited to 90mph-- probably for the best. The kids still like getting the back end kicked out tho.... so does dad.
Oh- fastest I've ever been was in a 1988 GTA Firebird: 133 on the digital speedo. Too fast for a 2-lane 40mph posted road. (Is there a holy-crap-I-was-young-and-stupid emoticon?)