I know Ice+Electric and Dragon+Fire(Unresisted including abilities on Reshram) what are the other ones?
Bolt beam is resisted by lanturn the magneton family, and shedinja. Ghost and fighting isn't resisted by anyone. Dragon fire is resisted by heatran. And finally, dragon water is resisted by empoleon and shedinja. Those are the best attacking combos in the game. Hope this helps and have fun abusing these combos!