I don't know about you but I feel like I wear my slip-on tennis shoes way more than I should even admit. They are just too easy to throw on as I am running out the door, plus they are comfortable.  One of my personal favorites is the Superga Canvas Slip-on. Right now you can grab a pair for only $19.95 (regularly $60) plus free shipping.  They are available in black, mushroom and navy colors BUT sizing is limited so grab a pair while you can.