This another one of these threads where everybody espouses their favorite saw. Some will argue for the most versatile saw, others will go for the most durable, on and on it goes...
The true test of what saw is "best ever" would be whichever saw so dominates it's niche in the market that there are no other competitors that come close. If you like a Stihl 090, then someone else will argue that a 3120xp is as good. If you like a 272xp, someone else will tell you to get a ...whatever.
There is only one saw that seems to completely dominate it's niche: Stihl MS200t, or any of it's similar predecessors. Some folks will argue that some other top handled saw is as good, others don't like it's balance or boxy shape, but I have never heard a convincing argument that it is not the best of it's kind. The fact that it is the most preferred saw used by climbing professionals says it all.
By the way: it is ridiculous to keep offering up as "the best saw" something that is sporting a bunch of aftermarket modifications. All the talk about porting (and other mods) instantly makes a machine "one of a kind", and unworthy of consideration in this thread.