Epic Super Sentai moments
 

Liveman - 5 member team henshin
Zyuranger - Geki and Burai's quest for the thunderslingers
Kakuranger - Jiraiya vs Gali
Carranger - Minoru's epic adventure to get the giga booster back
Megaranger - 5 Megablues
Timeranger - Timefire debut battle
Gekiranger - Gekitouja debut
Go-onger - Sosuke soul (episode 12)
Shinkenger - Henshin and battle with Gold
Gokaiger - the whole show is epic

Dekamaster's debut battle was quite epic.

As was the Shinkenger rollcall were they met Dayu for the first time.

Dekaranger - Dekamaster debut
Magiranger - First legend mode transformation
Shinkenger - Hime Shinken Red debut
Goseiger - Brajira's reveal (say what you want about Goseiger, I thought this was epic)

And yes, all of Gokaiger was epic. It'd be wrong to just pick one moment.

Ohred's first Choriki Henshin in Ohranger episode 1.

ZyuRanger - Geki's untransformed battle with Burai
DaiRanger - Jin's first full on battle with Ryo.
KakuRanger - Sasuke vs the Flower Ninja Team on his own
GoGoV - Red shooting the bird monster pointblank to save everyone
TimeRanger - TimeFire's death
AbaRanger - AbareKiller's dino form upgrade when he saves Rije
GekiRanger - Rio using the Five Deadly Venoms as a throne

I'm not sure what episode it's from since I'm not that far in the show yet, but there's an episode near the end of Dairanger where the heroes are depowered but they go into battle anyway. It all starts with the face actors pulling off the elaborate role call poses that the suit actors had been doing. It's pretty damn awesome.

Now I remember! The Dekamaster debut battle where he takes down 100 alienizers. :P I agree Brajira debut is a good one

Could we count VS Sentai movies as all being epic...?

stupid miyu bird in battle fever j series and he talk too much