Galen killed a lot of troopers.
Galen killed a lot of rancors.
Galen pulled a Star Destroyer from out of the sky.
Galen defeated Darth Vader and held off Palpatine.
Galen must be OP, right?
Princess Leia takes that spot in my opinion. Leia and Galen are the only characters I know who got tossed into space and survived. But whereas Leia saved herself by flying into the ship and waking up a few minutes later. Galen spent six months being rebuilt on the Empirical, a high tech mobile research laboratory, after being retrieved from space by a droid.
And if you think Galen is impressive, you should read Maul Lockdown. Maul not only kills a Yuuzhan Vong warrior with his bare hands but he also kills a Wampa bare handed. All without the Force too.
Galen is still my favorite character though.