Edit: I have driven all those cars as my Father is a car dealer. From this list, Lexus and BMW are my fav. BMW especially if you want performance and handeling. But if yor after ride quality, i say go for a Mercedes.
With the global warming, I wqould definately go with an hybrid. Toyota and Honda have great ones too.
But if you definately want a sports car, I would go with a WRX STi, I conviced my mom to buy that car (for her) when I was 16 and I never regretted it
Seriously this car kills all the new cars you will get for under 50 000 dollars and is 4 wheel drive, which is also great. Its not too luxurious but its built like a tank.
If you buy it and you have the money for the gaz (and dont care about global warming) this is the way to go!
But again, I wouldnt recommend to my mom to buy that car again with what I know about global warming...