Here you go:
DIY Storage Ottoman from Soul Style
Large ottomans provide so much function and style to a room. They can be used to prop up your feet, store toys or blankets and serve food in a tray.
Small & Colorful Storage Ottomans from Design*Sponge
Not only is this nursery cute and colorful, but with the help of the small storage ottomans, it's also very calm.
Great Accent Ottomans Under a Console from House of Turquoise
I love this setup for multiple reasons: 1) the ottomans provide storage and extra seating, 2) it's out of the way and 3) it allows parents of young kids to display items that are out of reach! I also love this color combination. It's so vibrant!
an Ikea Expedit as Window Seat from Ikea Hackers
This Ikea hack (turning an Expedit on its side) is a great use of space. It also, of course, provides great storage underneath with the woven baskets.
Ikea Expedit with Dresser Drawers from Cape 27
This Expedit uses two dresser double drawers and two dresser single drawers to provide storage as a dresser/changing table. This would be great in the living room to hide away toys and display some pretty, child-friendly pieces.
Ikea Billy Bookcase with Cabinet Doors from Ikea
Last but not least are the Ikea Billy Bookcases with cabinet doors. A few of these would look great as a built in with decorative pieces and books on top and kids' toys on the bottom.
This is by no means an exhaustive list, but it provides several options (a little heavy on the ottomans I know). Do you have any other ways to conceal toys in general purpose living spaces?