A tote bag is the perfect everyday bag. It will fit all your essentials - exactly what you want from a bag on long days in the city.
If you can afford it, then what you're looking for is this Valentino Tote Bag. It's more expensive but worth your money. While you're at it, also have a look at this Valentino Tote Bag. Yes, this item is expensive, but it does not mean it's not worth it.