Houston, UCF, UConn, Cincinnati, and yes, even Memphis. We've played all these schools recently and the games have not disappointed.
The more I think about it, the more I feel like deregulation could be great for BYU. The P5 realignment chaos would pretty much die down. BYU could then join the AAC with Boise St., SDSU, and Air Force, and get the AAC to guarantee an 8-game conference schedule with annual games against Boise St. and SDSU - and more Air Force, Navy, Houston, UCF, Cincinnati, and UConn and minimal Tulsa and Tulane.
With deregulation, you wouldn't need divisions - so, BYU's schedule could look like this:
SEPTEMBER
PAC
PAC/B1G
UConn/Temple
UCF/USF
OCTOBER
Utah St./Hawaii
ACC/SEC
Cincinnati/ECU
SMU/Tulane/Tulsa
NOVEMBER
Houston/Memphis
Air Force/Navy
SDSU
Boise St. (rivalry)
We would play for the Conference Championship opportunity each year - plus have post-season flexibility with the following likely bowl destinations that would actually choose BYU:
1) NY6 (Fiesta and Cotton most likely)
2) Las Vegas (v. PAC)
3) Liberty (v. SEC)
4) Armed Forces (v. B1G or Big 12)
5) Poinsettia (v. MWC or PAC)
6) Hawaii (v. MWC or CUSA)
(St. Petersburg and Military v. ACC and Birmingham v. SEC would also be part of the lineup, but not likely to pick BYU).