EF 100-400mm F/4.5-5.6L IS (already have it)
EF 70-200mm F/4L (still searching)
EF 100mm F/2.8 Macro (still searching)
EF-S 17-85mm F/4-5.6 IS (already have it)
EF-S 10-22mm F/3.5-4.5 (still searching)
And for fun:
8mm Samyang/Falcon/Bower or Vivitar 7mm Fisheye (still searching)