Toyota and Lexus because they are reliable (a1998 Lexus LS400 has fewer problems than a brand new 2006 Mercedes ML500), safe (Camry had a five star crash rating, Mercedes E Class only had four star, according to NHTSA), high tech (Lexus Advanced PreCollision System, which can monitor drivers face and road obstacles including pedestrians, Mercedes' system only monitor cars and metal objects, Lexus's can brake themselves in emminent collision), good value, good engineering, comfortable, fuel efficient, environmentally conscious (most of their cars are at least rated ULEV II, even their v-8 5.7L engines with 380 hp are ULEV II), , more power yet less environmental impact (their 270 hp v-6 can get up to 30+mpg, still ULEV II), and their hybrid tech has come a long way in terms of practicality (from Prius to the new Lexus LS600h L, a hybrid with more tech than a rolls royce, and is a hybrid with 430 hp). It's future seems good too, with its upcoming Toyota Supra, Lexus LX570, Lexus IS-F, and the ~$200,000 Lexus LF-A. Oh, they also have recently becaome the US's and the world largest car manufacturer, surpassing GM. Instead of cutting jobs and closing down plants like Ford, Toyota is opening up new plants in the US, creating jobs and helping our economy.
http://www.lexus.com/fcv/
http://www.lexus.com/models/LSh/
http://www.youtube.com/watch?v=Lrk6vsb77xk
http://www.youtube.com/watch?v=YfZDtC9kjVk
http://www.consumerreports.org/cro/cars/which-companies-make-the-best-cars/overview/0407_best_cars.htm?EXTKEY=SP72C00&CMP=KNC-CROYPICARS&HBX_OU=51&HBX_PK=pi
This one's kind of old:
http://www.caranddriver.com/article.asp?section_id=15&article_id=7359
http://www.cnn.com/2006/AUTOS/01/23/american_cars/index.html