I have to say, I honestly don't see Andrew Ryan as the truly most tragic villian. It might be my own personal reservations on Objectivism, but it is not on my opinion that a real life Rapture would be built on anything less than Avarice. And as time goes on in the story, the more information you get on Andrew Ryan you find that while he had grande aspiritions, they were so seeded in intolerance and heartless dismissal of his citizens that they no longer meant something. And plus he's based off of Ayn Rand, so he probably raped somebody (and rape is wrong).
My mot tragic villain is The Master from Doctor Who. In the old series, the Master was basically the Time Lord equivalent of special ops, sent after a rogue Doctor by his own government, paid n regenerations. So, he's kind of like the Time Lord's Hero, and he keeps getting killed off by a guy in a funny scarf. But if we were to consider the New series as cannon he was damned to an insanity orchestrated by a corrupted Time Lord Counsel from the very moment he looked into the void. The Master had no chance, he was simply a victim of high grade insanity. He even ran from it, tried to become normal and inhabited the body of a helpful scientist. But even then, cruel fate as would have it, that it would all return. He then was killed by his wife (but to be fair he did enslave humanity), and then brought back by, I don't know, Magic? But was brought back with a condition that required him to kill people to stay alive.
And worst of all: his entire life, his one purpose was to act as a catalyst for the Time Lords to return. Yes, his entire life he was meant to be a tool. So to review: insane special op, who is orchestrated by his government to take down a rogue agent, driven insane by both the man he hunted and the people who gave him orders, killed over and over to the point of delirium, only to find out that he had zero control on what he does, that it and his path had already been chosen for him.