Two Pokemon that can fit on any team are Hitmontop and Specs Gastrodon.
Gastrodon WILL score you OHKOs as it is extremely easy to switch a fire or ground type out for it and the +1. Immune to Discharge, Surf, Water Spout. Resists Heat Wave and Rock Slide. Such a solid Pokemon.
Hitmontop is awesome with Intimidate, Fake Out, Wide Guard, Detect, Mach Punch, Sucker Punch, Close Combat. It has sooo many amazing doubles tools that it is like it was made for this metagame.
Also, to chime in on the Stealth Rock discussion... I find it hard to set it up on an offensive team without losing momentum, but incredibly easy with a stall team. They help a lot against Focus Sash, Tornadus-T, and Kyurem-B if you can get them up. It also helps a lot if you force a lot of switches. For example, Earthquakers encourage flying, bug and grass types to switch in. Softening them up with Stealth Rocks helps score some crucial 2hkos.