Not only that size, it also has to be not in the South. The Houston Metro is hot garbage. DART makes Dallas quite a bit better, but if you miss a bus transfer you're screwed. That's the fourth and fifth largest metro areas in the country.
Edit: Houston does have light rail but it's so bad that I forget it exists. There's a plan to make it better which is great, but it won't be ready until I'm ready to retire to the country.