i am a canon kind of girl. i can't tell you why, but a canon was my first camera starting out and i have just stuck with it. although, if nikon called and offered a lucrative contract with equipment included, i could be convinced to switch (yeah, right).
here is what's in my bag now:
canon 5d mark ii (aka "bo"), canon 40D back-up
16-35mm L
24-70mm L
70-200mm L
50mm 1.2 L
35mm 1.4 L
28mm
85mm 1.4
what stays on my camera most of the time? probably the 24-70mm or 50mm.