I'll chime in with some thrillers that are Whispersync deals:
The Bullet, by Mary Louise Kelly, is $2.99 at
Audible if you buy the Kindle e-book for $1.99. (I've listened to this one and enjoyed it.)
Everything She Forgot, by Lisa Ballantyne, is $3.99 at
Audible if you buy the Kindle e-book for $1.99. (Haven't read this, but did listen to Ballantyne's
Guilty One, which was excellent.)
Someone Out There, by Catherine Hunt, is $3.99 at
Audible if you buy the Kindle e-book for 99 cents. (Bought this but don't know anything about it.)