Just wanted to point out that the F-111 was originally designed as a Navy interceptor under the “TFX” program. It wasn’t until Robert Mcnamara, and his “wiz kids” decided to cut costs that it also had to be an Air Force Bomber. The plane that ended up being produced as the F-111 was way to heavy for carrier work and a naval version was never built. The Navy still wanted their interceptor, and ended up with the F-14 “Tomcat”.
As for the most underrated fighter? Well I always thought the F-5E and the one off F-20 were better than most people thought.