ESR of Ceramic Capacitor
While ESR is not always given it is often easy to find on a better manufacturers website.  Many have online or downloadable tools that will show you all of the information you could ever want about a cap.  With the rise of the need to simulate PDN for everyday boards, people have been demanding exactly this kind of information.

For example take a look at Murata's simsurfing tool 


It's free of course and all you do is select a capacitor from the list and among other things you can see the graph of ESR and impedance vs frequency.  If you're simulating it's easy to extract a simple RLC model from the data.