Cotton Woven Bath Rug - Restoration Hardware.  I swear by these...durable and easy to clean.

RH's Cotton Woven Bath Rug:Our cotton woven bath rugs feature unmatched quality, texture and absorbency.

Recycled Towel Bathmat

Turn Old Towels Into A Soft, Sophisticated Bath Mat

Plum & Bow Connected Stripe Rug - Urban Outfitters

Connected Stripe Rag Rug