My guess, just like for any design, there really isn't any best (there could be worsts tho!). The reason is that everyone has individual characteristics that fit one design better than another.
If you are talking about quality, I have "assembled" CL Arfs Top Flite (2), Brodak (4), Sig (1), and to be honest, there is something to like and dislike about each one. (If I would include RC versions, I would increase the number of TF and Sig, and add a few new ones). I won't say which is/was my favorite, since over a season that will vary! Build wise I found all easy to put together with some common sense. I did not convert them into "rebuild" kits however. All could be upgraded, no doubt, but the same comment would also apply to the kit versions of each too!
All are still flyable, invarious states of readiness.