I have no real desire do all the illicit things that invisibility would enable. Flight would make many things in life more convenient, and that's really hwat I need at this stage. Things be a bit easier.

Invisibility because you can hide and move about in secret. You could make a great spy. There are too many obstacles already in the sky
Also, fly too high and it gets cold and less oxygen.

Flight! I love it when I fly in my dreams.

Invisible. You can see and do anything you want. No questions asked.

Flight because it might come in handy, though I'm afraid of heights.

Invisibility, nope. I'm already practically invisible in society.

Definitely invisibility! You could easily ride in the cockpit of any plane for free. Only downside to invisibility, it does raise your creeper level up a notch!