Today only, Best Buy has the Logitech M325 / M310 Wireless Mouse in 13 different colors and designs for $9.99 (reg. 19.99). I would suggest picking this up in-store for free or shipping is free with purchases over $35.
The Logitech M325 Wireless Mouse has a contoured shape and soft rubber grips and great reviews. Currently, these are priced around $17.00 on Amazon, so $9.99 is a great deal.