I find a detective buddy to pair up with and we go around solving crimes together.

Haunt some of the powerful but evil people in the world and see what I can change. Let's see how effective a dictator like Kim Jong Il can be with a ghost all up in their business.

If I have poltergeist abilities then I suppose just straight up assassinating people would be possible. After all, if you can shove a book off the shelf or flip a light switch then breaking a few tiny blood vessels in someone's brain to give them a stroke is going to be easy. Not that killing other people would be easy, but maybe as a ghost I'd have a different perspective on death.

I'll play but what are the rules here? Can I move objects? Do people hear/see me? Ooh, can I possess people?

Spend the first hours exploring my limits.. how high can I float, how fast, walk through walls etc. Then go places I shouldn't be.. listen in on stuff. With all the UFO/alien stuff lately I'd go to Area51 and snoop around.

Ruin the technology of my enemies

Get together with my floating friends and have a floating party fun.

Complain, mostly.

Finally get through my r adding backlog. With nothing to distract me and no need to eat or sleep, I might actually finish it in a few decades.

Since I presumably can't play video games anymore without hands, I'd probably watch others play games over their shoulder and judge them for not playing the same way I would. If they made a really bad misplay I'd probably turn into a poltergeist and start throwing stuff

Test to see if i can take over a person's body like the movie Heart and soul, then problem just help them do or say the things they want to.

Like a guardian angel, but useful.

Interesting. I absolutely would horrify people. Especially children. Like ruining their sleep. Mess with them until they are admitted to the funny farm. Grow a habit out of that and do that over and over again, in different areas of the world until I become a legend of a nightmare that actually comes true.