6th gen...
The plane will have an AI. It will interact with the pilot in aiding the combat situation.
Plane will have a 360 degree LPI radar coverage of more than 70 km range all aspect. Future radar will not only be hard to detect, it will be able to create false signals for the enemy.
New forms of stealth designing/material combination will be developed so that ACM compromises will not be made like in todays stealth, bringing back the design of the plane to pre stealth days of optimum air performance.
Experimentation of new technology to enable humans to beat the 9g limit in todays fighters so that future pilots will be able to take more G's or at least the unmanned craft flown by AI will be able to do these manouvres.
Heat seeking guided canon bullets.
Some form of 1st gen visual stealth.
thats all can think of for now.