3. Dark Phoenix (X-Men: The Last Stand)
I was torn about whether or not to include the Phoenix, but ultimately decided to for two reasons: 1) I was encouraged to by readers following the 25 most powerful heroes article. 2) It is essentially a completely different entity to Jean Grey, possessing her, and therefore not actually her at all. She possessed the same powers as Jean, whose telepathic abilities allowed her to use Cerebro (a device Professor X created to amp his telepathic powers) to track down Rogue and Magneto, which is impressive in itself, but her powers weren't strong enough to use it properly and, although she did manage to locate them, the machine drained her considerably and made her faint. Regarding her telekinesis, Jean was able to disarm a missile despite the fact that it was out of her sight, she assisted Storm is knocking a pair of fighter jets off course and she was able to hold back a massive amount of water in order to save her friends. As the Phoenix, these powers were amped and her telekinesis was powerful enough to move individual atoms, which gave her the power to literally disintegrate anything or anyone - such as what she did to Professor Charles Xavier - and her telepathy was such that she had the ability to exceed Xavier even in mental power.