1. GoogleX
  2. Google neXus
  3. Apple Mac OS X
  4. Apple Xcode
  5. HTC One X
  6. Google Solve-for-X
  7. SpaceX
  8. IBM X-force
  9. Motorola Moto X
  10. Microsoft Xbox
  11. Comcast Xfinity
  12. Sony Xperia phone
  13. Dell XPS tablet
  14. X-treme tablet
  15. Motorola Xyboard tablet
  16. Nokia X

No where, outside, of the tech world is the letter “X” gets such a prominence.

Update (Feb 24): added Nokia X.