I see evok's point about his definition of "gotta have" and why he says Toyota has a lot of them. However my (and Camino and the others) deffinition of "gotta have" implies more than being successfuls sales wise just because people think it's the best qualitty (Which, especially in the Camry and Avalon, is not true), or that groups like CR tell them Toyota is the best buy. Our definition of "gotta have" cars are cars that are bold, distinctive, and create a strong emotion towards the buyer/owner. Very few people lust after a Toyota Camry or Avalon because of the power, handling or "style" they have. To that end, I believe a few example of "gotta have" cars are thes three.
Chrysler 300
Dodge Charger
Ford Mustang
They are prime examples of gotta have cars. Not only are they disctive, creative, different, and American in their style, but they have performance and value to back them up. RWD, powerful engine choices (excludng the base 2.7 in the 300 of course). People genuinely love these cars, and not because they are a Toyota, as most people who claim to love Toyotas state as their reason for loving them (most people I've talked to anyway). but because they are cool, different, and unappologetic. And to top it off, they sell very very well. (also the 300 recieved the most awards of any new car in history I believe). That, I believe, is our deffinition of "gotta have"