Since Round Rock is the least known, perhaps you could add that it's home to Dell Inc. Not sure if that would help or not, but at least it would add some significance.
Because everyone knows that West Texas A&M is in Canyon, duh... No spending 43 of my 47 years in Texas helps.. As does being nerd about what cities are home to universities. So I know all about towns like Boone, Normal, Moscow etc.
That didn't turn out too well for the Texans, although it is special to me. While attending a friend's wedding in San Antonio in 1974, my future husband and I got engaged. I'll always remember the Alamo. :)
I aced it btw :)