For the purposes of this post, the term "integrated" will be referring to being tied into the vehicles hydraulic system (not "built into the dash").
You did ask about the "best" brake controllers, and while the Prodigy P2 and P3 are certainly the king of their class of controllers (don't even consider a time based unit), there is something better. An "integrated" brake controller is a far better solution than any inertia based controller like the P2 and P3. It is the only way for the trailer to work 100% seamlessly (smooth) with the tow vehicles brakes, and does so in forward and reverse, at speed or while crawling into your favorite site. Unfortunately, they are not as widely available as standard controllers. Both the MaxBrake and Brake Smart controllers were integrated into the vehicles hydraulic system, but neither is being produced any more (not enough people share your "best and not necessarily the cheapest" point of view). You may be able to find a used one or possibly an NOS unit. Otherwise, there is a new controller on the market (earlier this year?) called the DirecLink. I have no personal experience with it, but it is "integrated" with the tow vehicles brakes via the on board computer (OBII). Vehicle manufacturers have finally caught on to this supremacy as well, and are now offering computer controlled integrated brake controllers (with the added bonus of being built into the dash at the factory).
My post is sure to be followed by those defending their precious Tekonsha Proportional controllers, but rest assured...if you want "the best", then you want an integrated controller. Otherwise, the Prodigy P2 or P3 is the next best thing, and good enough for most.