pokedump!
RBY
Slowbro
~ Reflect
~ Amnesia
~ Surf
~ Rest
We are all familiar with TobyBro right? This is TobyBro that lost TWave for Reflect! Amnesia doubles Special (+2 SpA / +2 SpD), making Slowbro rather impenetrable from the special side, outside of the frequent Thunderbolt crits :( It has great physical bulk and resistance to Psychic moves to start setting up. Many players neutered Slowbro with Explosion; iirc it's 340 move in RBY, and unlike in DPP and BW your slower Pokemon's turn ends after Explosion, allowing the opponent to finish off Slowbro with a second hit from a different Pokemon. With Reflect, however, Slowbro is guarded from Explosions and Self-Destruct, making it nigh invincible to take out without a crit :) This Slowbro is especially fierce mid- late-game when the opposing team is sufficiently paralyzed (you esp. want Chansey paralyzed, as 999 Special Slowbro barely misses a 2HKO on her).
GSC
Electabuzz @ Leftovers
~ Thunder
~ Screech
~ Cross Chop
~ Ice Punch
Thanks, Jorgen for remembering Electabuzz :) I think I've seen Flameout ~5 years ago using this set, and it really struck a cord with me (although I think he used Fire Punch > Ice Punch). Electabuzz has impressive 105 Spe and less impressive 95 SPA, but its versatile movepool and Thunder's raw power more than makes up for it. Thunder & Ice Punch forms the mighty boltbeam combo, whereas Cross Chop pretty much takes out the rest, most notably Snorlax, Blissey, and Tyranitar. Screech is the crux of the set, though - once this move connects, Cross Chop is doubly effective - even Raikou, the premier non-Ground / non-Blissey Electric sponge, is a 3HKO after the defense drop (so no Rest-stalling :d). Combine Screech with Cross Chop's 25% to crit and you have a Pokemon that forces lots of switches. Electabuzz is a great way to pressure the opponent, and can clean late-game. Skarmory and to a lesser extent Water-types / Gengar are free switch-ins for Electabuzz to start some table-flipping. Spikes support is very much appreciated.
Meditate is another option, but unfortunately, it does not provide the heavy damage output that Screech provides. Meditate's Atk boosts also dies with Electabuzz's demise - Screech's effect lingers as long as the opponent's mon does not switch out; the latter scenario is often preferable, since Electabuzz is more of a guerrilla player.
Here's a cool replay against Earthworm that does not really show Electabuzz in action, but still cool nonetheless!
Here's a log that better shows Electabuzz action when it is on a roll.
ADV
Swampert @ Salac Berry
Trait: Torrent
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature (+Spe, -Atk)
~ Substitute
~ Endeavor
~ Hydro Pump
~ Ice Beam
You will be in for a surprise if you were expecting a defensive Water-type when you see this Swampert! This is a Sub Endeavor set that takes advantage of Sandstream damage to finish off the opponent after an Endeavor! With full special attack investment, Swampert hits surprisingly hard with Hydro Pump and Ice Beam, so Endeavor is not the only trick up its sleeve. Especially after Torrent, STAB Hydro Pump will be punching holes! Swampert is a slow Pokemon, but is fast enough to make use of Salac Berry to reach 360 Speed, which makes it faster than Gengar and Starmie with only 352 Speed. Initial sluggishness actually comes in handy, because against a faster Pokemon Swampert can often keep its Sub intact when Salac Berry and Torrent activate, shielding Swampert from retaliation should the opponent survives a hit / takes an Endeavor.
TTar is a mandatory partner. I also appreciate Sleep inducers such as Breloom, Milotic, or Gengar, to bring in Swampert safely. Rapid Spin support is also necessary, since it may screw with Swampert's health, thereby making Endeavor less effective. With Spikes cleared, you can switch out Swampert and bring it back in against snoozing / slower Pokemon (it's slow, but it DOES have respectable 240 Speed).
DPP
Heracross @ Leftovers
Trait: Guts
EVs: 32 HP / 252 Atk / 224 Spe
Adamant Nature (+Atk, -SAtk)
~ Swords Dance
~ Close Combat
~ Megahorn
~ Stone Edge
DPP provided Heracross the one thing it needed - Close Combat! Now it can finally break through Skarmory by itself! Most people initially used Choiced Heracross, but it makes Heracross easily wallable. Make it a Swords Dancer, though, and Heracross becomes a very effective wallbreaker.
I can give it Life Orb or even Toxic Orb & Facade to make a Heracross a literal nuke, but I respect Heracross's decent defenses, which allows it to take stray special and Fighting / Ground hits; thus Leftovers. This Heracross pairs well with Lucario :d