E6 General.
Ok, let's do this.
Feats: Due to E6's nature, feats that grows exponentially stronger the more of them there are become more attractive in E6. Psionic feats are probably the most notable, but there are others.
The Luck feats from Complete Scoundrel are one of these, allowing a growing amount of re-rolls for various situations.
Another one is the Shifter feats in Eberron Campaign Setting and Races of Eberron. Since Shifters gain additional shifts per day equal to half the number of Shifter feats they have, the more the merrier.
Speaking of Racial Feats, Goliaths in Races of Stone have them as well. Choosing the higher of two saving throws, two initative checks, caster level checks, skill checks or two attack rolls are all good things.
Builds:
Wizard.
Race: Grey Elf (Monster Manual pg. 104).
Base Class: Wizard 5
Prestige Class: Mage of the Arcane Order 1 (Complete Arcane pg. 48).
Strength:8
Dexterity:16
Constitution:12
Intelligence:20
Wisdom:10
Charisma:8
Base Feats:
1 Collgeiate Wizard (Complete Arcane pg. 181).
3 Metamagic Feat of choice.
5 Cooperative Magic (Complete Arcane pg. 76).
6 OPEN SLOT
Aditional Feat Suggestion:
Expanded Spell Knowledge
Expanded Spell Stamina
Ability Training (INT)
Ability Advancement (INT)
Alternative Class Features:
Generalist Wizard (Races of the Wild pg. 157)
Notable Things:
Starts with 11 1st level spells and gain 5 each level for free.
Starts the game able to prepare 4 1st level spells at 1st character level.
Prepare one additional spell per day more than a normal wizard, must be of the highest level known.
Access to the Spellpool, call up to three levels worth of spells per day.
+2 bonus to Knowledge (arcana)
Fighter
Race: Goliath (Races of Stone pg. 56)
Base Class: Fighter 6
Strength:19
Dexterity:10
Constitution:15
Intelligence:10
Wisdom:14
Charisma:8
Base Feats
1 Power Attack
3 Improved Bull Rush
4 Knockback (Races of Stone pg. 142).
6 Shock Trooper (Complete Warrior pg. 112).
Aditional Feat Suggestions:
Improved Sunder
Combat Brute (Complete Warrior pg. 110)
Weapon Focus (heavy mace, morningstar or greatclub)
Cleave
Three Mountains (Complete Warrior pg. 114)
Leap Attack (Complete Adventurer pg. 110)
Goliath Racial Feats (Races of Stone pg. 142).
Alternative Class Features:
Dungeon Crasher (Dungeonscape, pg.10)
Notable Things:
When you hit while using Power Attack, you can make a free bull rush attempt against the target you hit.
The PA number is added as a bonus to the opposed Strenght check, the number is doubled if you wield the weapon in two hands. Don't provoke AoO and you don't move with the enemy.
When you bull rush an enemy into a wall or solid object, you deal damage equal to 8d6 + 3x Str.
+4 competence bonus to saves and AC vs. Traps.
+10 bonus to Strength checks to break doors, walls or similar.
Able to shift the penalty from Power Attack. Instead of a penalty to hit, it becomes a penalty to AC. Only on charge.
Some other tricks regarding bull rush.
DFA idea:
Dragonfire Adepts are very nice in E6. Here's the Handbook, for quick reference:
http://community.wizards.com/go/thread/view/75882/19870954/The_New_Dragonfire_Adept_Handbook!
They got their battlefield control schtick with the Entangling Exhalation/Slow Breath combo at level 5.
Do EE breath first round, then Slow next, then EE, then Slow. EE has a d4 rounds duration and Slow breath is 2 rounds, 1 on save.
With a bit of luck, you can keep your opponents continually Slowed and Entangled.
Slowed:
A slowed creature can take only a single move action or standard action each turn, but not both (nor may it take full-round actions). Additionally, it takes a –1 penalty on attack rolls, AC, and Reflex saves. A slowed creature moves at half its normal speed (round down to the next 5-foot increment), which affects the creature’s jumping distance as normal for decreased speed.
ENTANGLING EXHALATION [BREATH]
You can use your breath weapon to create an entangling mesh of energy.
Prerequisites: Dragonblood subtype, breath weapon.
Benefit: When you use your breath weapon, you can choose to enmesh all creatures in its area instead of producing its normal effect. Your breath weapon deals only half its normal damage; however, any creature that takes damage from your breath weapon becomes entangled and takes an extra 1d6 points of damage, of the same energy type as normally dealt by your breath weapon, each round at the start of your turn. This effect lasts for 1d4 rounds. If your breath weapon doesn’t deal energy damage, creatures damaged by the initial breath are still entangled but don’t take additional damage on later rounds.
Entangled:
entangled: Ensnared. Being entangled impedes movement, but does not entirely prevent it unless the bonds are anchored to an immobile object or tethered by an opposing force. An entangled creature moves at half speed, cannot run or charge, and takes a –2 penalty on attack rolls and a –4 penalty to its effective Dexterity score. An entangled character who attempts to cast a spell must make a Concentration check (DC 15 + the spell’s level) or lose the spell.
That's 75% movement reduction, -3 to attack rolls (-5 if it uses DEX for attacking, such as ranged attacks or Weapon Finesse dudes), -3 to Reflex and AC and can take only a move or a standard action. That's not bad at level 5.
Just keep skirting on the edges of your breath weapon and adapt your movement to you opponent and it's going to slowly die without ever reaching you.
Note that you can't do EE and Slow breath on the same turn, since EE requires you to damage the opponent and Slow Breath have no damage.
Play any race that gets a CON bonus. Like Mongrelfolk (Races of Destiny pg. 99), Dragonborn (Races of the Dragon pg. 8) if possible.
Also, I love E6, E8 and the Gestalt versions of both so I'll probably be back with more ideas later.