I can easily see Forretress using the moveset:
Toxic Spikes/Spikes
Rapid Spin
Gyro Ball/Earthquake
Pain Split
Pain Split really just replaces Explosion/Rest on the standard set.
Also Pain Split Rotom would probably use something like:
Discharge / Shadow Ball
Hidden Power [Ice] / [Fighting]
Will-O-Wisp / Reflect / Overheat
Pain Split
It's pretty much the same as the Rest Talk set but with an extra move.
Edit: @nJoyUrAIDs It's a decent idea but you're usually better off Baton Passing to Marowak or Medicham who can hit hard without setting up.
Also, on the topic of Belly Drum, Magmorter might be able to make use of it.
Magmorter @ Salac Berry
6 HP / 252 Atk / 252 Spe
Adamant
Flame Body
Belly Drum
Substitute / Thunder Punch
Fire Punch
Earthquake / Thunder Punch
Pretty much the same set as Charizard but Magmorter doesn't get crippled by Stealth Rock and doesn't really have any use for Endure. With Adamant and Belly Drum, you atain an attack of 1268, compared to Charizard's 1172. The main advantage Magmorter has, is that is can actually use Stealth Rock to forgo Substitute and use Thunder Punch for better type coverage. Unfortunately, Magmorter can't outspeed Timid Choice Scarf Heatran after the Salac boost and you shouldn't use Jolly because Charizard would be slightly faster and more powerful with Adamant.