Originally Posted by Ellye
Quints: Flat health bonus are great for everyone.
Red: You'll need two types here: Magic Penetration and Armor Penetration. The first one is useful for more champions, though.
Yellow: Dodge and Armor (flat or scaling) are reasonable for everyone. Mana Regen is great for all champions that use mana.
Blue: Cooldown Reduction and Magic Resistance (flat or scaling) are useful for almost everyone.
You can skin on the dodge runes, and armor unless you want to tank, and dodge is just very expensive, the others fit perfectly in pretty much every champion except the ones that do not wear mana, in that case you can always get something like attack speed.