According to me ;-p

PvP

1. Nighstalker
2. Gunslinger
3. Bladedancer
4. Stormcaller
5. Sunbreaker
6. Sunsinger
7. Defender
8. Voidwalker
9. Striker

PvE

1. Defender
2. Sunsinger
3. Nightstalker
4. Voidwalker
5. Stormcaller
6. Gunslinger
7. Sunbreaker
8. Striker
9. Bladedancer

It's a wee bit more nuanced than all that, I think. Part of why I can't quit this game.

PvP 6v6

Gunslinger
Striker
Bladedancer
Stormcaller
Voidwalker
Defender
Sunsinger
Nightstalker
Sunbreaker

PvP 3v3

Nightstalker
Sunsinger
Striker
Bladedancer
Stormcaller
Defender
Voidwalker
Gunslinger
Sunbreaker

PvE

Synergy is more important than individual classes. Defender + Nightstalker + Stormcaller is my favorite combo.

Just curious, why striker last?

I think putting Striker/Bladedancer on the list at all for PvE is putting them too high.

PvE

1. Defender

I like this human. He understands.