If you want European, used BMW 5 series, MB E class and Audi A6 are all good choices...
If you want American, Ford 500, Taurus, Chevy Malibu, Impala and Chrysler 300 are options you can buy them near new with your budget..
If you want Japs, Camry, Accord, Mazda 6, Nissan Altima and Maxima are not bad...