OBDII scanners

I was thinking about buying a scanner but I need some help on which ones are any good. So far I was looking at the Actron cp9145, the kal equip 9640 or the autoxray 6000. Do any of you guys own one of these. Which one do you think is best. What is the difference between these. If there is any other brands please let me know. Thanks for any help

I bought an Auterra A-300 unit( http://www.auterraweb.com/ ) on ebay for about $190, and picked up a used color palm for another $40. Does what I need it to do as a "backyard" mechanic. So far, it's worked on every car I've hooked up to with it. It allows you to record and store up to five sensors/parameters, view in meter, bar graph, and dual graph modes. Seems pretty good for the money, though the instuction manual(CD/pdf) could be better. I couldn't see just buying a code reader without being able to look at sensor outputs in real time in order to troubleshoot what was really going on. This seemed a good compromise between a reader and a more expensive analyzer. I bought the one (A-300)that is also compatible with the new CAN communication standard, which my 2004 Ford uses, and will be industry wide by 2008.

I use the Actron 9145. durable, reliable, and you do not need anything else. $149 at most parts stores.