I find videos made using a helmet mount to be nauseating.

I usually place mine on the handlebars. But what I think looks nicer but is more difficult to achieve is mounting the camera to the frame so it is not affected by handlebar movement. The little side to side movement of the handlebars becomes very apparent if you want to speed up your video. Mounting a camera directly to the bike anywhere picks up absolutely every mechanical bike sound from the shifters to the chain going through the rear derailleur.

If you don't have suspension the video can be shakey with weird vertical squishing. Wrapping a piece of old tube around the bar might help. At least with the chest mount your body acts as a shock absorber for the camera.

Let me say that on a wheel is not the best place:

Downtube looks kind of neat: