Fein, Festool

Fien, if you have the big bucks if not you cant go wrong with milwaukee,makita,or bosch. never been a dewalt fan.
Fein, Festool

"Best" is highly subjective, without some defined criteria.
Longest lasting (durability), best battery life, best selection of tools to fit that common battery, best value for the dollar, most powerful in a given size, etc.
I don't think anyone is going to throw craftsman out there as a candidate for "best", but that's what I use, and cannot fairly make a complaint.
Pros in their favor are a fairly broad selection of tools, and a good value price. The 4.0Ah Lithium batteries have made a remarkable improvement in tool performance (their NiCD's are absolute garbage). I have their new brushless 1/2" drill, and it has been thoroughly impressive. I can run it side by side with my old (11 years old) 1/2" drill that still runs great (durability, no?).
Cons are the tools are not always the most powerful available (I have a 1/2" impact wrench specifically in mind here), and the fact none of them are sold WITH the 4.0Ah XCP battery (Have I mentioned their NiCD batts are garbage yet?).
It is true, and no, it doesn't mean a thing. The only guys that believe the two lines are at all similar performance-wise are guys that own Ryobi. Maybe that's all you need at home, and that's fine, but let's not be delusional.
Surprised that name isn't more popular in cordless tools. No experience with them myself. A buddy informed me that's all they use at the Ford plant.
I know people that own and use Panasonic. I have used them myself. And they are nice and seem to last forever..Brand awareness isn't as high in America, and they price themselves out of many other markets. You've got to pay to play with their stuff.
Panasonic manufactures some of the absolute best, no compromise, no nonsense products on the planet.
Now, this next part isn't meant to be an argument, or Panasonic pimping. It's simply an observation of how people can fool themselves.
"Best" in regard to "personal preference" may be somewhat subjective, but quality and performance are not subjective in the slightest. Those aspects can be quantified, and the results can be compared to similar offerings.
I don't put much stock in "personal preference", either. You either need a 1/2 inch drive 90 degree 350lb/ft battery powered impact wrench or you do not.
There's nothing subjective about that.
Not even compromise between heat evacuation versus resistance to water ingress, and other things of that nature are "subjective". Neither are considerations such as battery systems you may already have, weight concerns, or affordability.
That's still objective. You're merely dealing with facets of the product, it's use, and your own lifestyle that may or may not be specifically useful or warranted in your environment.
Other factors matter, though. I don't personally own a Panasonic power tool. I haven't been able to justify the purchase price until recently.
Subjective aspects are things such as brand preference, and whether or not you like blue, white, or red.
Panasonic has equals. I'm not saying you can't buy the same or better. The top shelf is certainly not empty, and they draw the line at a certain point. They simply don't try to compete where they don't stand a chance.
One can pick out the absolute best long pattern 1/2 inch combination wrench for a specific application if he tries hard enough. The thing is, not all of us need the best.
Not all of us make logical choices, either. I could have bought a vehicle better suited to some of my uses. I didn't. I like what I have, and I've gone out of my way to make it work.
I like S-K tools. Snap On makes quite a few tools that would be better suited to some of the tricky bits I encounter. That's me being subjective, and unwilling to pay more.
We've got to admit when we make compromises, and not simply chalk everything up to subjectivity.

Briefly skimming through the thread I didn't see Hitachi mentioned and feel as if they definitely deserve consideration. I have no experience with most of their offerings, but I bought the DV18DL 1/2" drill/driver/hammer drill back in 2007 and it has never let me down on any task. I carefully compared this drill to the top end offerings from other brands at that time and have no regrets whatsoever. The raw power, pack longevity/steady power output, pack recharging, tool balance, etc. has served me well on tons of projects.
FWIW the main task I had in mind when I purchased it was using it to bore holes in oak/hickory stumps that would later be burned. This involved boring dozens of holes in each stump using an 18" x 5/8" auger bit and the DV18DL had absolutely no problem burying that bit hole after hole. Actually impressed me to say the least. Good luck on your decision as it probably won't be easy.