David: In my personal experience, it is not the quality of the CAMERA that makes the film good, but the quality of the CAMERA OPERATOR, and perhaps more importantly, the FILM EDITOR (I happened to be both). If you have a half-decent camera (one that when, on a tripod, shoots video that is acceptable for viewing on a TV), it should be fine. I've been managing over the years between my high school's Sony Handycam Digital 8 and my personal JVC
camera which records to miniDV tape. I've found that while the quality of the video stays the same, a TREMENDOUS improvement can be made simply in the stylistic assembly of the video. I started off making crappy little montages (that I shudder to watch now because they were horrible) with iMovie, and changing nothing but my creativity, moved on to making some rather artistic movies that were fun to watch and make. Sometimes I use Final Cut Pro, when I feel like it, or Photoshop for other effects. Other than that, it was just my brain and my camera. You don't necessarily have to spend big money to upgrade your camera/computer/software unless you're really looking for super-high quality video and audio, and it might not be worth it depending on what you're going to be using the video for.
I've just violated Winston Churchill's rule: "A sentence ending in a preposition is something up with which I will not put."