Oblivion for me is absolutely world class, isn't being cared for like a world class coaster, but it is one.
Admittedly I haven't ridden any other dive machines, but even looking online, the only one I've seen that looks anything like as outright intimidating is G5 and that's because they built it so high up, it makes the cars look small! Clever use of terrain, much like Nemesis but of the opposite order. For those that haven't seen it's reversed twin:
(Credit, TPR)
That also gives you some sense of exactly how far down Oblivion goes!
Now, think about the problems they had building The Smiler, and take a look at just how far underground that drop goes, it's an extraordinary feat of engineering, imagination, and sheer absolute audacity to create something 16 years ago that to this day maintains an intimidation factor I STILL feel every time I go around that turnaround.
Nemesis, Stealth etc, The Smiler, all my favourite UK coasters are tamed after a go on it or two, but I know many people who still find that ride a right "parp" machine after goodness knows how many goes round it.
A truly ground breaking, excuse the pun, piece of design and imagination, which for it's time was absolutely incomprehensible.
Just as too was Nemesis.
And that's what Alton Towers used to be about.
THAT is why it had magic.