/diy/ - Do It Yourself

So in stores and on the interwebs you have many, many different tool manufacturers:
>DeWalt
>Makita
>Milwaukee
>Ryobi
>Kobalt
>Craftsman
>B&D
>Ridgid
>Hilti

Now what I want to know is which one produces the best-engineered/most reliable tools. Obviously you face differing prices, accessories, availability, tool variety, voltage/torque/amperage/etc., and other factors. In your experience, what would you say the best tool manufacturer is for the typical /diy/er, someone who might use it a few times a week, wants something that isn't going to break and halt ones progress, and has the accessories/power to get the job done?
How about purchasing used tools on craigslist and Ebay? I would imagine the batteries might be depleted to an extent, and the tools will obviously possess some external wear and chips, but brushless motors should be somewhat fine after use so long as they aren't contaminated or overheated/physically shocked(Dropped).