I'm calling this "Fey Strike" as the group i'm playing is using 2 Eladrins to deliver it. Basicly the fighter (with help from the warlord) will deal lots of damage to a single target in a single turn.
Level 3 combo.
Spearman (Fighter, preferably Eladrin, for Eladrin Soldier), with Encounter Power Rain of Blows and daily Villain's Menace
Tactical Warlord = Int 18, Tactical Assault feat, Tactical Armor if possible would come a good way. Powers: Warlord's Favor and/or Lead the Attack.
The warlord hits with either Lead the Attack or Warlord's Favor (selecting the fighter to get the bonus) to give +5 (or +6 with tactical armor) to hit the bad guy. This is the hardest part in the combo, and that's why you need both Warlord's Favor AND Lead the Attack. If one fails to hit you try again next round.
The fighter then, moves into flanking position (Fey Step helps if simply moving would prove too difficult) and hits with Villain's Menace. Shouldn't be that hard to hit as you'll have +7 or +8 plus your regular attack bonus.
If you hit, Villain's Menace will give you +4 to damage till the end of the encounter, the bonus to hit is irrelevant since it won't stack with Lead the Attack.
Next, the Fighter spends his Action Point and proceed with Rain of Blows.
Due to Tactical Assault, all his Rain of Blows attacks will get +2 to hit and +4 to damage (or +3/+5 if the warlord has Tactical Armor).
The math:
To hit: +1 (lvl 3), +1 (fighter weapon training), +1 (magic weapon), +3 (non-optmized Str), +2 (proficiency), +2 (flank), +5* (lead the attack), +2* (AP "Tactical Presence")=
+17 to hit (or +19 if Warlord has Tactical Armor)
Assuming you're lvl 3, and that with a "2" on the dice you'll be hitting AC 19, then this is pretty much enough to hit anything at this level, unless you roll 1's (which happens). Either way, it's very likely that most of your Rain of Blows attacks are going to hit, if they do, that's 4 attacks.
Damage: 1d8 (spear/trident) +3 (Str) +2(Eladrin Soldier) +1(magic bonus) +4(Villain's Menace) +4(Tactical Assault, or +5 with armor) =
1d8+14 (or +15) per hit.
Assuming 4 hits = 4d8+56
Considering the damage from Villain's Menace (2d8+10), it's alot of damage for a Defender in a single turn...
Keep in mind that this is not fully optimized. Fighter could max his Str, use a longspear, or even use the Spear two-handed.
Also, remember we're talking about 2 lvl 3 characters.