Just some ideas from Denmarkia. Since im not the most well-informed person out there, I don't know if any of these effects have already been invented.
MAGIC DISSOLVING
Each hit causes an effect equal to that of Dispel Magic. Using the wielders caster level to determine the effect, the target is affected as by a Dispel Magic targeting the highest level spell on the person. It can also be used on people who wish to get rid of a negative-effect spell, even though it be used to dispel anything but the highest level spell affecting the target (the wielder rolling a dice to determine which spell is dispelled, in case of more spells of the same level affecting the person).
Greater Magic Dissolving affects it's target on all hits
Equal to a +4 bonus
Lesser Magic Dissolving only affects it's target on critical hits
Equal to a +2 Bonus
GOD-HATER
A person suffering a critical by the weapon gains spell resistance 35 against divine magic for the next 1d6+1 rounds. Any divine spells already in effect have to penetrate the spell resistance or be dispelled. This means that not even healing spells or potions can be used. If the target is a divine spellcaster, he has to penetrate the spell resistance when casting spells himself, even if the spells aren't cast on himself. GOD-HATING weapons cause 2d6 points of extra damage against any kinds of Outsiders, including demi-gods, deities and avatars.
The wielder of GOD-HATING weapons takes 1d4 points of damage / spell level from any divine spell cast on him, both harmful and beneficial spells. Thus, Cure Light Wounds would heal 1d8+CL hit points, but cause 1d4 points of damage as well.
God-Hater counts as a +3 bonus
JESTER
A JESTER weapon is blessed by the gods of humour. Any time a person makes a fumble while wielding a JESTING sword, he is healed of 1d8+5 points of damage as the gods of laughter and joy bless him for lightening up their day. This effect of a JESTING weapon only happens when the wielder is fighting opponents for real. It doesn't occur when undertaking friendly training fights with allies.
Jester counts as a +1 bonus
Im not sure about the effective + bonusses. Im not good at that part of creating magical items (and I hardly care when creating some for my players).
MAGIC DISSOLVING
Each hit causes an effect equal to that of Dispel Magic. Using the wielders caster level to determine the effect, the target is affected as by a Dispel Magic targeting the highest level spell on the person. It can also be used on people who wish to get rid of a negative-effect spell, even though it be used to dispel anything but the highest level spell affecting the target (the wielder rolling a dice to determine which spell is dispelled, in case of more spells of the same level affecting the person).
Greater Magic Dissolving affects it's target on all hits
Equal to a +4 bonus
Lesser Magic Dissolving only affects it's target on critical hits
Equal to a +2 Bonus
GOD-HATER
A person suffering a critical by the weapon gains spell resistance 35 against divine magic for the next 1d6+1 rounds. Any divine spells already in effect have to penetrate the spell resistance or be dispelled. This means that not even healing spells or potions can be used. If the target is a divine spellcaster, he has to penetrate the spell resistance when casting spells himself, even if the spells aren't cast on himself. GOD-HATING weapons cause 2d6 points of extra damage against any kinds of Outsiders, including demi-gods, deities and avatars.
The wielder of GOD-HATING weapons takes 1d4 points of damage / spell level from any divine spell cast on him, both harmful and beneficial spells. Thus, Cure Light Wounds would heal 1d8+CL hit points, but cause 1d4 points of damage as well.
God-Hater counts as a +3 bonus
JESTER
A JESTER weapon is blessed by the gods of humour. Any time a person makes a fumble while wielding a JESTING sword, he is healed of 1d8+5 points of damage as the gods of laughter and joy bless him for lightening up their day. This effect of a JESTING weapon only happens when the wielder is fighting opponents for real. It doesn't occur when undertaking friendly training fights with allies.
Jester counts as a +1 bonus
Im not sure about the effective + bonusses. Im not good at that part of creating magical items (and I hardly care when creating some for my players).