FLOR modular rug tiles. They are amazing! So many choices to create your own design, and very easy to clean if you own a pet or have kids.
A great safety solution for floors; Foam hardwood flooring, maybe for a play area for the kids without having to lose the affect of the existing hardwood flooring already installed. Simply put it on top of the existing floors. Also used as an option to cover floor areas for Seniors at risk of falling.
Unfinished basement flooring for kids...
Screened porch: 5/8 inch Soft Tiles - Interlocking Foam Floor Tiles protect & cover floors in rentals from the kids & all their crafts & toys on the floor.
Contemporary Basement Playroom with Barn Doors
Kids playroom floor.
modular carpet tiles (Heaven Sent, $14 each; flor.com), which are relatively inexpensive and durable. If a truly disastrous spill leaves a stain, you can replace the individual tile, not the whole rug.