I know this is probably the most asked question here. But I'm trying to figure out why certain times some characters seem way more powerful than their whole teams (young Jean Grey, Scarlet Witch, Magik, etc) but still get depicted as "not that powerful". In my opinion (BTW I'm only familiar with the last 2 years worth of X-Men comics in Earth 616). I believe the list goes as follows:
Again. This is only MUTANTS that for the most part LIVE ON EARTH and part of the main Marvel Universe (Earth 616). Not omnipotent beings or heroes that were given their powers in other ways (Galactus, Thor, Hulk, Silver Surfer, Captain America, Phoenix Force, Thanos, etc.) Also this is a list of current characters with their current powers. Not Magneto at his prime, not Hope Summers with the Phoenix Force, etc.
1) Scarlet Witch - Probably the best mix of experienced and full of raw power.
2) Young Jean Grey - Super powerful but still learning to control and focus her powers
3) Legion - Too many personalities and unstable
3) Magik - Her powers are a little warped right now but she seems to be getting back to her own after some lessons from Dr. Strange. Also, she controls everything if she takes the fight to Limbo.
4) Rachel Grey - One of the top telepaths, very experienced, and has other useful abilities.
5) Iceman - Although sometimes he doesn't seem that powerful, he is pretty much indestructible. A little vulnerable to telepathic attacks but in terms of physical attacks, he is pretty unstoppable.
6) Franklin Richards - I believe he is considered a mutant. And could beat anyone on this list in the future. But in his young current stage I believe he is nowhere near his full potential.
7) Tie (Psylocke & Emma Frost). Both strong telepaths, both skilled fighters, both experienced, both ruthless. Both Sexy. haha.
Honorable Mentions: These probably have a say in being up here but I don't know too much about their current status or powers