Gwar: 'Pussy Planet' (1992) & Nirvana: 'Rape Me' (1993)
Burnt By The Sun: 'Dracula With Glasses' (2002) & Pig Destroyer: 'Baltimore Strangler' (2012)
Mad Season: 'I Don't Know Anything' (1995) & Silverchair: 'Slave' (1997)
Biohazard: 'Cornered' (1994) & Type O Negative: 'All Hail and Farewell To Britain' (2007) - specifically the 3:43 mark...
Eyehategod: 'Blank' (1993) & Dr.Doom: 'Prophesized Disaster' (2012)
Temple Of The Dog: 'Times Of Trouble' (1991) & Pearl Jam: 'Footsteps' (1991)
This one doesn't really count as it was pretty much written by the same persons; never-the-less remains as two different songs from two different groups...