What causes the tilt on axis?
For the Earth, there are many theories, but the one that is accepted is that millions of years ago a meteorite hit the earth at an angle, causing it to tilt. It is also possible that the moon was formed by the debris that shot out of the earth when the meteorite hit it.
Mercury's axis tilt is 0°. Venus' axis tilt is 177.4° (or 2.60, depending on "north pole" definition). Earth's axis tilt is 23.5°. Mars' axis tilt is 25.2°. Jupiter's axis tilt is 3.1°. Saturn's axis tilt is 25.3°. Uranus' axis tilt is 97.8°. Neptune's axis tilt is 28.8°. Dwarf planet Pluto's axis tilt is 122.5°.