Yakolev Yak-28P supersonic interceptor for use until something more modern comes along.
Mach 1 at sea level, Mach 2+ at 10,000m.
Very benign handling all round. Slow take-off and landing speeds and lots of wheels mean it’s quite easy to land, too.
The bicycle landing gear can cause a slight veer while on the ground, compensate with the rudder. On take-off you can balance on the central gear above about 50 m/s, on landing be sure to correct for it. AG2 toggles cockpit SAS modules if you’re having trouble taxiing.