"But... But I want to be a big karate cyborg... ;_;" - Nik Hasta
"Get off my lawn! ...on this forum, that just makes people think of Cyclops." - Sharpandpointies
"...makes me think the Night King just says "Screw the rules, I have magic money" when it comes to physics." -Captain Morgan
General AI is a matter of time, if humanity doesn't wipe itself out or something.
It's certainly far more likely to be achievable in the real world than all the other crazy stuff that many of the characters on the list can do. Given that the characters have already worked out how to do this, I may already have a general idea of the scope and requirements of what I need to do. From there, it's a question of actually implementing it.
Now if we get the ability to "magically" just do all the things that the characters in the lists can do, then there are probably more impactful options. But going by real world stuff, achieving straight up technological singularity is probably what would have the largest impact and kind of lets you then transition to the other areas of science and technology that need attention.
The desirability aspect isn't relevant for me since this is something people are trying to do anyway. Responsible AI is extremely important, but it's a different topic from trying to achieve some form of progress, be it on an individual level or a societal level.
Heck, even if I can't achieve technological singularity, I can almost certainly automate all my day to day tasks, which itself is a huge bonus.
Each of these has a distinct superpower included as part of the package.
In addition to asking myself which skill-set most appeals, I'm also considering the superpower. The power that most appeals is Julian Bashir's super-memory and genetically-enhanced processing. It seems like something that would simply be extremely useful in all walks of life.
The scientific knowledge is a really big bonus, though. Not sure what I'd do with it. Retire to the country and run experiments to learn about the true nature of reality and so forth.