
stephanmaigc comments on the old Victorian floating systems which, ironically, is where a lot of the idea behind the Copperfield flying sprang from; the Kellar and Kalanag flying systems being key bits of focus (the Kalanag getting my vote for being one of the most sensational levitations around... but, that's why it's been in Lance's show for so long).
When it comes to naming "the best" of anything, we have to remember that it's subjective. Line up a single effect like the Thin Model Sawing, one each by twelve different builders then look at the deception factors, construction techniques, material quality, finish, comfort and ease of use as well as set-up & break-down, durability factors, etc. When you start allowing your perspective of magic to grow into this kind of fine-tunning you can have your idea of what is "the best" shifted a bit.
On this particular front I'd have to say that Mark Wilson's "Diamond" styled Thin Model Sawing (built by John Gaughan) is the sweetest of the pack and Kirby Vanburch's Asrah Levitation couch is one of the most deceptive I've ever seen (his switch is likewise the cleanest in the business).
Such a broad area to look at, it's hard to say that any one piece is better than another in that it's the performer and technical crew that transform the box (as it were) into a miracle.