Whats the ‘sweet spot’ for buying cars now?

Back about 10 years ago when I was starting to drive, the best deals were to aim for cars 3-4 years old because thats when they were fresh off a lease, probably well taken care of with minimal milage and 30-40% off MSRP. Now when I look at cars 3-4 years old, they are only 10-20% off and sometimes even selling at new car prices. What would you guys say is a good deal when shopping for used cars now?