OOF! I'm a bag hound but I have yet to find the one true bag.
Most days, I use a Vera Bradley bag with the six pockets because it holds all of my work stuff and still has room for my laptop in a sleeve.
I misplaced the sleeve, so I started bringing a Timbuk2 messenger bag that belongs to my partner. It's nice! But not particularly roomie.
I have a million purses (and am going to do a bag purge in the next month or so) but I use only 2-4 regularly. If I have a bag for work or a diaper bag, I don't bother to carry a purse. I just throw my wallet into whatever bag I already carry.
In terms of diaper bags, I had one custom made from Happy Tushies
. It's a little unstructured, but I love it dearly because it has my favorite sushi fabric lining it.
I should look for a nice computer bag, but ugh.