It is worth remembering that:
MiniDV cassettes record in a compressed form. eg jpg compression for each frame only.
DVD camcorders use MP2 which adds a temporal compression with master frames every second or so. (Terrestial TV uses MP2)
HDD/SDcard camcorders use MPeg4 which is a heavier compression than MP2. But alledged superior encoding. Superior quality is not assumed.

All compressions are lossy which means that any video editing, particularly: fancy flying intros, titling or morphing etc has to decompress and re-encode so there is a loss of quality with each generation.

For this reason I would say DV cassette for heavy video editing use.
DVD (if still sold) for unedited archiving/convenience.
And for HDD/SDcard (etc) camcorders I would personally opt for HD versions because it is the future and it does compensate for any losses in encoding, somewhat.

Do you have a DVD writing facility? Most people want to share their videos. I usually edit the video and then make the DVD in Nero, which allows me to add slideshow effects and audio tracks very simply. I also do some slideshowS in Pinnacle and Adobe Premiere as well but always try to edit AVI files (the least compressed form) until the Nero/DVD stage.