Death, Gontyna Kry, Immortal, Abigor, Carcass (if they played grind again), Disciples of Power, October Tide, and more that I can't remember right now.
At the gates
Emperor
Einherjer
Death(the original lineup)
Led Zeppelin(if they made another Led Zeppelin IV)
Metallica(original lineup when kirk hammet joined, not with mustaine)
At The Gates
Pantera
Immortal
Emperor
Death
Led Zeppelin
Nirvana
Soundgarden
At The Drive-In
Sanctuary
Carcass
Rage Against The Machine
The Police
The Ramones
The Sex Pistols
The Clash
Snot
emperor, immortal, the crown, dissection (i dont think jon will find anybody else), at the gates, and windir (how the fuck can that dude die of hypothermia?)
Cynic, Emperor, Carcass(they are so much much better than Arch Enemy), Death, Maudlin of the Well! I know there's Kayo Dot...but I really prefer Maudlin of the Well's songs.
Almost every band I can think of has been mentionned...except Ebony tears which is not my favorite band but I still enjoyed their stuff once in a while.
Keep in mind some people would need to rise from the dead for some of these to happen!
AC/DC-I love Bon Scott era AC/DC and would really have liked to see them with him live.
At The Gates
Buckcherry-I thought they were a good replacement for Guns 'N Roses type hard rock.
Carcass
Death
Down-Phil is wasting his time in SJR in my opinion...
Led Zeppelin
Morbid Angel with David Vincent. Might happen someday but I doubt it. I just cannot get into them with another vocalist and I have tried numerous times.
MegaDave with the Rust In Peace lineup.
Pantera
Sepultura with Max. This needs to happen...
Witchery