There isn't ONE in my mind that is perfect but...
Well for me, suction isn't everything and in my mind there isn't ONE perfect cylinder vacuum with straight suction but quite a few good models that do the job very well. None of them are however, bagless because I've only ever had a few bagless cylinder vacs and found them to be annoying and noisy.
Henry is good and durable but a bit too old fashioned for my home. I like sledge type vacuums that are compact enough and have tools on board. Henry's tools can't be stored, which is why I was a fan of the James model for many years...
So, for me any of the old Miele S300s, S500s and models like the S5000 and S8000 that have the tools hidden under a flap for easy access are great - unlike some U.S members however, I find the tools on the Miele to be of excellent design even if the short crevice tool is noisy.
Any of Bosch's bagged cylinder vacs
Any of Electrolux's bagged cylinder vacs, even if both brands persist in using friction fit fittings.
The old Hoover Telios from the 1990s - even the old Hoover Studio nee Morphy Richards/Goblin Compact/900 vacs are fab, though their tools aren't as good.
Also SEBO's straight suction C, K and D series with lightweight non-embedded corded hoses, of course.