My most effective and powerful character is probably my Earth / Psi dominator pre-nerf psychic Shockwave.
She mowed throw mobs while hardly taking a single hit, and this was also when she was still 46 not even 50. When she finally got to 50, she was unstoppable.
Side note: I realize that Fire/Psy was the go to farming build back then, but I always hate the idea of fire powers.
My most fun is any controller / dominator with Mind Control. When CoV first released (I was like what... 12 and idiotic), I constantly underestimated the Dominator archetype. Later when I couldn't pay for the Subscription fee, my friend told me about Guild Wars and rolled the Mesmer (rip gw1 mesmer). Then when I finally saved up money to play CoV/H again, I rolled a mind control dominator and I was blown away.
I rolled Mind Control because hey, Mesmers were basically Mind Control medieval controllers. Fell in love with not only the archetypes, but the power set too
So far, no other game I have ever played has matched the ability of control given to the GW1 Mesmer and CoH/V Controllers/Dominators. I have fun disrupting and controlling enemies, not seeing big damage numbers on a computer screen (although Mesmers and Dom/Controller can output some high numbers anyway
)