It's a confusing time to buy a camera. Lots of new formats that sales people appear to be telling lots of lies about just to sell stuff.
This is a very basic guide to the pros and cons of the various and many formats out there.
1) Standard definition (SD) DV tape.
Slick to edit, only requires a moderate fast pc, a 2 gig pentium is enough.
Cameras are cheap as chips new and so cheap as to be almost disposable if you buy used. Some real bargains to be had as people swap to hdv. Pro SD gear is a steal.
2) HDV - tape ( same tapes as above)
Needs more power to edit, dual core minimum, four advisable. Long rendering times on slower systems.
Now available for sensible prices, but be aware that to get the best from this format you do need to spend a considerable sum; the quality of the lens and other optical components can limit camera performance. Cameras that claim to be 'HD' but cost less than a cheap DV standard def cam will NOT produce results worthy ot the format.
These two tape formats are what I would reccomend for the keen film maker. The following formats use more compression and consequently require more cpu power to edit smoothly and have slightly poorer picture quality as a result of this extra compression.
3) DVD SD.
Dics can be played in many dvd players, a selling point for many. Easy to edit but the data is much more compressed and the cameras often perform badly in situations where the camera is getting knocked and shaken.
4) Hard drive cameras, SD and 'high def'.
Video is often very compressed so you really will benefit from a very fast PC. Many editors wont even accept this data. Hard drives are fragile in portable devices. Convenient as you can often get 7 hours or more on a drive.
5) SD card cameras.
The future, but not yet unless you spend £5000. Consumer cams are really compromised by poor optics (often) and very high compression.
A note about HD, hi def, and so on.
Stickers proclaiming ' hi def ' are being slapped on all sorts of tat to sell it - it's often bullshit.
To achieve a decent pic you need a good lens and that dont come cheap. The raw pixel count is almost irrelevant. Nobody rides for free on the quality express.
A 150 quid camera may have a zillion pxels but you really do get what you pay for. Dont be a pixel whore ! ! If you are buying a camera, compare the output from several at different price points. IGNORE the sales pitch, unless you really trust the shop.