My main camera bag (a store-brand photo backpack) was becoming a catch-all. It took me longer to UNLOAD all the gear I didn't want to carry that day, so I stopped carrying a bag and would only carry one camera body and one lens.
Now I've switched everything into a wheeled toolchest, the red metal kind with the shallow drawers. Now all my gear is organized and accessible, and all my camera bags are empty.
That backpack is still my most-used bag, and I typically load it with an MZ-S, a K10D, a Sigma 24-135, Pentax 50/1.4, Sigma 24/2.8, Nikon SB-26 and SB-28, flash bracket, a roll of Ektar 100, Arista II (APX 400) and Superia 400, extra K10D batteries, circ pol for the 24-135 and 50, yellow filter for the 50.