Originally Posted by Fat Project_Mars
This. A lot of teams are going to have at least 1 dragon type and 1 steel type. (Some may substitute a sp. def sponge though, mostly for draco meteor in that case.) so there's that too. Also three major 'mons that he didnt list are Metagross, Heatran, and Cresselia. Cress especially because she is very, very common.
Shocked at the lack of Hitmontop, Garchomp, Chandelure, Terrakion and Tornadus in your lists. A bunch more like Zapdos, Sableye, Whimsicott, Ferrothorn, Excadrill, Hydreigon, Jellicent, Ninetales, Reuniclus, Scrafty and Suicune are common enough that you should consider them as threats when teambuilding, too.