Just a pure opinion question, there is no wrong answer as long as you justify your choice.
Now, the question is in the title, this is not the same as "what is your favorite" class, but simply which you think is easiest to beat heroic with.
I personally think a hot hydro is the easiest to beat heroic with. he has a good amount of health (and vitality from equips) so he can at least survive the onsluaght of powerful attacks in Z5, and every attack he does usually hits for over 2k at Zone 5 (so a consistent hard hitter, not a nuker though). Basically, I think he is the easiest to beat heroic with because he does good damage and has possibly the highest vitality of any class in the game (supposing that you don't go just for vitality equips or put attribute points into vitality).
You don't have to have done heroic mode to reply to this thread, as even from playing on easy mode you would get a gist of how each class would do in heroic mode. I beat heroic mode witht he hot hydro anyways, and it was easy except for the baron (hot hydro is an awful matchup against the baron).
I just beat the game on heroic and the only class that i've played is electric psycological. But that class only was only easy in the middle of the game. In the beggining i couldn't do nearly enough damage sicne i went for health with tenacity. and at the end i was getting stuck on some non-boss fights. but all in all i'd say it's pretty good. Shock therapy does more damage than stated above if you have maxed out Charge Blood because you crit often enough to make it worth it. but the low health does leave a lot to be desired i had less than 5000hp when i beat the game on heroic with Electric Psycological build.
Yeah, electric psycho is probably the most powerful class in the game (4k hits unbuffed all the time). However, like you also said, they have low health as well, which is the reason I picked hot hydro over it.
