Come up with new, unique Runes for Riot to add

Runes kinda don't change at all except for values in between seasons. They never introduce new kinds, something I feel is a little... uninspiring.

To that end, use this topic to post up and/or discuss ideas for new runes to add to League, or to suggest things for the Rune system altogether.

I'll start with a few ideas:

Rune Effects

• You gain 1 gold (per rune) each time you attack an enemy Champion. This cannot trigger on the same Champion more than once every 5 seconds.

• +X% armor/magic penetration
• Your mana regeneration increases by 1% for every 1.25% of your missing mana. Requires 3 Quintessences to activate.

Rune System

• Eliminate the purchase of low-level runes.

• Allow player to sell low-level runes or upgrade them to high level.

One thing I'd really like to see is Quints that require you to take all 3 slots to activate a special effect. Adds a big cost, but a big bonus.