The Cattle Exchange - Canadian TX, is the best steak I have ever had.
While the Cattle Exchange is good, I'd rate it more in line with the Barn Door in Odessa, or maybe one of the better steaks at the Big Texan in Amarillo. I haven't found any better steak in Texas (and if we're talking about steak, you might as well exclude everything outside TX) than the Taste of Texas in Houston.