Persoanlly it depends on what you want to do.

I enjoy playing the economic game, so it's mage + any reasonable healer. So far my favorite is mage pally priest. Recently got into farming strat with that combo and do pretty good in there (on a good run, I make maybe 300 an hour, average run maybe 225).

pvp I'd struggle to know what the best is, I do pretty well with mage/pally/priest in that, but nothing super.