We have an entry way with both the front and garage entries at a 90 degree angle.  Ceramic tile.  Have been trying all sorts of rugs and ideas to see what would be understated but useful to collect soil.  The size is strange for rectangular, but this little 4x4 round rug is perfect!  The door closes over it nicely, and it adds a bit of charm as people come in our new home.  Soft, well made, and delightful!

Pros: good shape, durable, great dirt collector
Cons: none