I'd vote the death splinter to be my least favorite, too. Contessa has really bad winrates and I haven't found a viable combo, yet. Aside from the strong flying ability cards that are useful for earthquake battles, my favorite card is Jarlax the Undead. Used in sub 13 mana battles, he allows you to play 2 strong cards instead of just one tank plus fillers. Besides he can summon lvl. 2 commons at lvl. 1.
!BEER