I like hills. Even mountains. Long sustained steep grades, paved and unpaved. There are plenty of them in TX. Many of them are within a day-trip of the major metros. Let's list them here. Shall we?
1) The hwy climb to Chisos Bason, email@example.com ?
2 has to be the Fort Davis area, hwy's 166 and 118 in particular, and the spur rd to the McDonald Observatory.
2) Next up, the El Paso transmountain road?
3) Lots of legbreakers in the Hill Country. RR337 W of Leakey, etc.
4) 2.1 m @ 7% + near Amarillo, TX 207