Finding the best handbag/purse

I love purses and handbags. Now with that stated, why is it I CAN'T find one that suits ALL my current needs. It's summer and hot here so backpack style is out of the question due to perspiration issues. Over the shoulder bags are out of the question because it's cumbersome to try and run after 3 kids with a purse falling off your shoulder. I need a good crossover bag or sling that goes across my body but I find that those are too small to hold ALL the stuff I have to carry. I no longer want to carry a diaper bag because the kids are at an age where I can bring the diaper pad with me and leave it at the bottom of the stroller or leave the bag in the car until I need it. DH knows my fetish with bags and laughs at me everytime we go somewhere and I detour to the accessory aisle. If any of you have a recommendation...please send it MY way!
TIA!