I don't have a specific camera recommendation for you, but my video adventures with (i) the camera in my Samsung Galaxy Note 5 smartphone, and (ii) a high-end Canon 7D DSLR may be of interest. Like Iacopo, I'm an old photography buff with a lot of experience shooting stills. However, I'm fairly new to videography. I want all the things Iacopo wants in a still camera, but my videography needs seem to be quite different.
Why the camera phone usually works for me: For videos of tops in action, I've actually come to prefer the phone camera -- mostly for the autofocus and autoexposure features. The phone's image quality is plenty good enough for YouTube in 1080 HD, and it has important features that the 7D actually lacks -- most notably autofocus and autoexposure while shooting. It also has a fairly capable "pro" mode allowing some valuable manual control. Autoexposure can be turned off in pro mode, but I don't yet know of a way to disable autofocus.
For reasons I don't quite understand, the phone's low-light performance is much better than the 7D's, even at low manual ISOs. And at ~10% of the 7D's weight, it's also much easier to handle, albeit at the expense of increased shake. Tripod mounts for smartphones are cheap and effective. (I like Reticam products here.)
The biggest problems with the DLSR: When the camera-subject distance changes significantly during a shoot, the DSLR
must be refocused manually. And if exposure changes during the shoot, the correct exposure
must be recaptured manually as well. Canon views these as "professional" features, but I generally find them a royal pain in practice -- even in tripod shoots with both hands free. A professional videographer might be quick and accurate enough to maintain decent focus and exposure with the 7D and a moving subject, but I certainly can't! Lack of an assistant to handle the tops during the shoot (my usual situation) makes the problem much, much worse and often impossible. The great weight of the DSLR also makes it almost impossible to hold and shoot with one hand -- even with a grip.
Where the DSLR shines: The only time I turn to the DLSR for top videos now is when I need its aperture-priority mode (absent in the phone camera's "pro" mode) and its
huge depth of field. I also turn to it now and then for its interchangeable lenses and its ability to mount a polarizer. (The lenses mainly help me fill the frame without close-up distortion.) The DSLR's image quality is a little better, too -- but not enough to make me want to use it for video on a regular basis.
My
YouTube channel has many LEGO top videos. I don't hold these out as examples of what to do, as I'm still a pretty lousy videographer. The last video shot with the 7D is the one entitled "Technical LEGO: R-rail, a simple RC dragster".