With you posting your request in the videoscoping thread I assume that you intend to connect the camcorder to your scope. If so, I would recommend buying a camcorder with a small zoom, i.e. 10-12x. A bigger zoom range would probably cause severe vignetting due to the design of the optical elements.
However, if you intend to use the camcorder on its own or with a converter lens, by all means go for one with a bigger optical zoom range. I was in that dilemma last year and eventually bought a Panasonic SD90 which has a 26x optical (41x intelligent) zoom. I have had some great results with or without a 2x converter lens attached. This model has now been superseded but no doubt the newer models are worth considering.
One major thing to consider is sensor size. As with DSLRs, the larger the sensor generally the better the quality of image produced. With camcorders it is the same. Looking at the specifications you will note that the "cheaper" models with the bigger zoom ranges tend to have smaller sensors. This is not a problem if you intend to video fairly close subjects, but if you have to zoom in to maximum to get a decent sized image then that is where the quality of the image may suffer.
The quality of still images produced by camcorders is governed by the number of megapixels available. For example my SD90 can shoot 5MP stills wheras the higher priced and smaller zoom SD900 can shoot 14MP stills. To be honest the SD90 stills give a slight "watercolour" effect and are lacking in detail if you crop the image.
If you have a computer with a powerful processor and enough RAM to handle video editing in HD then I would strongly recommend buying a full HD (1080p) camcorder. The quality of the footage produced is far superior to Hi8 or MiniDV. You will not be disappointed.
If you already have a compact camera or DSLR that shoots in HD then the decision is not quite so straightforward in my opinion. In the past I have connected my 7D to my scope and shot video at high magnifications. In the right conditions it produced very good results but if the subject moved closer or further away it was very difficult to refocus without causing problems due to camera movement or vibration.
Hope all of the above is some use to you. If I can be of any further help please contact me by PM.
Good luck!
Mike