The stock tripods from Celestron are generally well matched for all models, however, some improvements can be made.
Naturally, one of the most important characteristics of a tripod is stability and the ability to dampen vibrations quickly. To insure you tripod is doing the best it can in this regard, start by checking to see that all the nuts and bolts are tight. Many have received tripods with loose hardware. Next, insure the center brace is fully expanded and tight. Then, only raise the legs at high as necessary for comfort. Longer leg extension allows vibrations to continue longer than necessary.
If it still seems your tripod takes too long to settle down after you tap it, perhaps you should consider the Celestron Vibration Suppression Pads. They are a little expensive at around $50, but they really work. The NexStar 60/80 will not generally benefit much from the pads though as the weight on the top of the tripod is relatively light and their tripod has nifty little rubber feet that act as shock absorbers.
The black Heavy Duty Tripod supplied with the NexStar 8/9.25/11 GPS is fine for alt-az use, but not really stable enough for EQ mounting with a wedge. The added weight hanging off the side causes things to shake at the slightest touch or breeze. From late 2004, Celestron started shipping the GPS line with a much more stable tripod distinguishable by its stainless steel legs. Many GPS model owners have elected to purchase and a adapt a larger tripod such as the G-11 or Meade Giant Field Tripod. In 2003, Celestron introduced a Super Heavy Duty Tripod (model number 93509) which is the same tripod used with the CGE series with the addition of an adapter plate. Before purchasing a replacement tripod, check to ensure your wedge will fit the tripod.
The Advanced Series CG-5 tripod provides good eyepiece height for the SCT and 6 inch refractor models, but for the Newtonian models it is another matter. The eyepiece location for the 8 and 10 inch Newtonian models require a stepstool when viewing near the zenith, even with the tripod legs at their lowest possible setting. Peter Bruce has written a very detailed article describing modification of the tripod to "bring things down to Earth". Click here to download the article in Adobe Acrobat format (reader available from www.adobe.com).
Another suggested improvement is replacement of the accessory tray. The supplied tray is just too small for many. In fact some of the models of tripods don't even have a tray, so variations of this suggestion might just do the trick. Try the pots and pans section of your local department store. Some have used pizza pans; I personally prefer a 10" cake pan. The cake pan is much deeper and I find that to be a good idea when handling my eyepieces in the dark. Basically, all you do is drill holes in the bottom of the pan and bolt it on in place of the old tray. You might also want to pad the bottom of the pan with felt or a sheet of thin rubber or foam. In the case of pizza pans, you will also need to drill holes for eyepieces to set in.