If you are not sure which class you should play, here is a quick guide for euroaion:
Assasin: step 1: buy double paralyze godstones.
step 2 : go hide
step 3: Buy razor keyboard / mouse and use Synapse.
step 4: use everything to kill your enemiy. If it dosen´t work, go hide again and wait for cooldowns.
When you kill your enemy, don´t forget to call him bad.
Cleric: Buy 100000 sets for every Situaion, otherwise no one will pvp with you and Don´t go DPS.
Chanter: Same as Cleric. Never go dps for group pvp. No one will take you, because everyone is tryharding and dodging Kamar / EoB to kill noobs.
Ranger: Not in this patch. Sorry. Even slideshots and kiting will not save you.
Templar: cLiCk tO MoVe MaCrO/SyNapSe, AHK spamm skills.
Gladiator: Same thing as Templar, but with more AoE and random knockdowns. Short: RNGESUS.
Sorc: if shock remove used, Aetherbind. If not, sleep your enemy for 2 minutes, until he has no skills to kill you.
If it dosen´t work use wintry and 10k shield. And don´t forget to push 3 buttons to cover Silence/Root your enemy.
Spiritmaster: The only thing they FEAR is you.
Gunner: Trrrr, trrr reload trrrr, trrr, your enemy is dead.
Bard: Do with your enemy everthing you wan´t. Sleep him, stun him, paralyze him, make him to your B***h.
And last but not least my favourite class Aethertech: When you wan´t to win every 1 v 1 and tryhard people, play this class. No skill required. Tank with dmg and cc´s from Sorc.
Feel free to add more ideas.