Fighter: 4e Essentials
~The fighters didn't have a/e/d powers, but relied rather on stances that improved attack or damage, or allowed some other action (One slayer power allowed the fighter to attack and move, one gave him a +2 to speed when charging. The knight had a stance that allowed him to push an enemy back and then follow it)
Cleric: 4e Essentials
~It's too bad they didn't add more domains to the two in the book: Storm and Sun (there was a "Shadow" domain, I think, presented in another book). The "Storm" Domain was the damage-dealer, and the "Sun" Domain was the healer/undead hunter (because of the radiant keyword in many of the attacks). Still, the time I played in a D&D Encounters session, I played a half-elf cleric (Sun Domain), and had a lot of fun. Attacking and healing or attacking and buffing in the same turn, being able to pull team mates from the brink of death, etc.
Rogue: 4e Essentials
~The Thief does quite a bit of damage, and, like the Essentials fighters, doesn't rely on a/e/d attacks. The thief has "tricks", which are based on movement, after which the thief can attack. It's difficult for the Essentials thief to NOT get combat advantage (depending on the tricks chosen), so she does heaps of damage every turn.
Wizard: 4e Essentials
~The Mage devotes his efforts into a primary and a secondary school of magic, which add elements to his attacks beyond damage and damage type (the illusion apprentice penalizes the attack roll of an enemy against whom he casts an illusion spell; the illusion expert gets a bonus to bluff and stealth checks, the illusion master forces an enemy to grant combat advantage).
As an aside: I prefer the 4e method of skills, with broad categories and a five-point bump to trained skills. The broadness of the skill categories allows a certain creativity to accomplishing tasks, in my opinion. For example, third edition had "craft armor", "craft weapons", "craft wands", "craft items". There is no "craft" skill in 4e, so one must improvise, perhaps using two or more different skills. For example, creating armor might take both Athletics (to beat the metal into shape) and Endurance (to be able to continue beating). One might throw in History (acting as a sort of a catch-all knowledge check) to show that the character actually knows how to turn tiny pieces of iron into chainmail. The Nature skill allows the character to know the proper type of metals to use. Make it a skill challenge!
There is a ritual for creating magic items and armor (which any character that has taken the "ritual caster" feat can follow), OR one could add in an Arcane check, along with the DM-required components.