I can't comment on "best" as that is entirely subjective and depending on ones needs, but for what its worth I would just like to add that I just recently got the Behringer X-touch
mini and it is just awesome for my workflow and my way of working. Granted I have only used it for a few days, but I am happy to report the mouse is being used less already and my neck says thank you as my posture is better which to me is huge!
Sure it looks more like a toy compared to the bigger sexier ones, which I initially planned to buy ( Mackie/X-touch/etc) but I thought about my actual needs and realized I did not need all those things (faders especially) and did not like the space required as it doesn't work in my setup. This thing combined with footcontroller/masterkeyboard mappings will cover a VAST amount of functions and features with me ever having to take my hands off the piano, which is what I want.
I want a controller to help me during writing and recording, that is the part of the process where I spend 90% or more of my time and where not having a controller was felt the most and where it help the most, to me.
I use the presents and AZcontroller from azslow3, and the thing just worked exactly as advertised by him, kudos ! :)
So enough of my rambling, if you want a cheap controller that is capable, compatible and wont take up space the mini is a great choice imo. azslow3 has good descriptions on what it can and cannot do btw so you don't have to guess.