Oh coasters, how I love thee. I have a bunch that are not nearly as fun as these and we rarely use them. That's the only reason I haven't stocked up on all the fun ones I find on Etsy all day.
Uncommon at Etsy
Scrabble Coasters: Avril Loreti at Etsy
Yours & Mine Coasters: Inbound Thread at Etsy
Mosaic Coasters: Ring Mosaics at Etsy
Felt Coasters: Felt Planet at Etsy