Obviously inspired by the ADV Best Friends thread. This thread is for discussion of Pokemon combinations in RBY that work particularly well together. I'll start with one I've promoted elsewhere, though I haven't used it much myself. Gengar + Articuno Defensively, the direct benefit of this pairing is that Gengar draws Earthquakes that let Articuno in for free. The really nasty bit here is that Gengar's nigh-immune to most attacks that aren't Earthquake, so there's no easy way around this - an opponent must constantly try to predict your moves to avoid getting screwed over (common scenarios: Gengar in vs. Tauros/Snorlax - Body Slam does nothing if you stay in, Earthquake does nothing if you switch; Articuno in vs. Tauros/Snorlax with Sleep Clause not activated - if they Earthquake and you stay in, they eat an Articuno Blizzard, but if they Body Slam and you switch they get slept potentially for free; Mega Drain Gengar in vs. Golem/Rhydon - if they Rock Slide and you stay in, they die, but if they Earthquake and you switch, they also die). Offensively, the pairing is absolutely stunning. Two of Gengar's main counters are Exeggutor and Rhydon, both of which are perfect fodder for an Articuno double-switch as it totally obliterates both with its STAB Blizzard. Articuno's two best counters are Starmie and Lapras, which are again perfect fodder for a Gengar double-switch thanks to its enormous Special and Thunderbolt (though the relatively rare Psychic Starmie can turn this around). And for the hat-trick, Gengar can Explode, which can take out any Alakazam or Chansey which tries to wall both and open up Articuno for a sweep. The biggest caveat to this pairing is that one must not be complacent in using it. If you're too careless and predictable, things can go south very quickly. I've seen people try to pull the Gar-Coon switch against Rhydon repeatedly in the same battle; this usually ends with Articuno OHKOed by Rock Slide. Know thy limits, know the risks, and know thy enemy. Lapras and Cloyster have similar offensive synergy with Gengar, but they don't work as well because they aren't immune to Earthquake.