Canon's f/2.8 Zoom Trinity:
16-35
24-70
70-200
You can't go wrong with that. It's expensive as heck, but it's well worth it.
OR you could go with the f/4 trinity (you have a 70-200 2.8, so dont worry)
17-40
24-105
70-200
OR you could go with prime lineup (which is troublesome and expensive as heck, but is well worth it if you can afford :P)
24L
35L
50L
85L
135L
200L
300L (f/4 is enough unless you shoot sports IMHO)
