Roots and GHEIST have been staples in ELO because of their bonus... even with their recent bans they're still popular. Freaks have the best damage bonus in the game and are (IMHO) a lot of fun to play. Also, even though they're not complete yet, I'm enjoying the heck out of the Huracan.
Vortex - expensive, but their bonus is a lot of fun.
Freaks - ridiculous DOT. Their best cards are expensive, though.
Bezerk - Elvis, Konrad, Melanie, Lola half is incredible.