Best overall - Baylor University Med center in Dallas (Yes, its a community program). Top boards scores. Tons of MRI experience, covetted MR fellowship either filled internally or by Mallinckrodt grads. Happy residents. Its run like an academic program. I would personally pick this over UTSW.
A very close second - UTSW in Dallas (Its SouthwestERN, not 'Southwest'). Best academic reputation in Texas and outside of Texas. Huge class size, top fellowships after residency, you can't go wrong here.
Then UT-Houston, then Baylor Houston, then all else.