Rejuvenation and nuclear fusion will probably be the biggest in terms of impact.

Those alone will annihilate most disease, poverty and hunger, solve any potential environmental issues that may or may not be an actual problem, and decrease prices of many luxury items so much that people will have a very hard time trying to make up bullshit problems, making it exponentially harder for government to make up excuses to grow like the cancer that it is.

The big scoop is the convergence of so many different technologies though. AI coupled with better algorithms, abundant energy to power ridiculous computing architectures, better materials and hence better hardware will lead to absurdly fast processing speed from question to ready product.

I'm most looking forward to the expansion of senses though, higher color and pitch resolution essentially turning shades of a color into entirely new ones, simulating more spatial dimensions (for games or movies), more flavors, or even some entirely new senses.