User blog comment:Ozuar/The Importance of Skill Order in League of Legends/@comment-216.36.26.248-20130329023306

Skill order, though important, is a lot less varied than the above seems to indicate.

Top, Middle, and ADC will typically max first the skill that has the highest base damage scaling. This is so they can cause the greatest amount of harm to their lane opponents. Otherwise, utility takes a backseat although most characters will want to have one rank in each by level three.

Jungle generally takes its clearing skill first. In characters that have them, this is whatever AOE skill they can spam. In characters that don't, it typically is their highest base damage skills. Most junglers have their ganking skill(s) by level three.

Supports generally max their heal/bubble skill first. If the support doesn't have one, they'll typically take whatever "close enough" skill they have, for example Blood Boil.

Skill order, though important, is less malleable for most champs than the OP seems to indicate.