Here's my dream roster

Heroes

Superman - Captain Marvel
Batman - Daredevil
Wonder Woman - Thor
Green Arrow - Captain America
Blue Beetle (Jaime) - Iron Man
The Flash - Deadpool
Nightwing - Spider-Man
Green Lantern - Invisible Woman
Swamp Thing - Hulk
Booster Gold - Cable
Hawkman - Wolverine
Grifter - Cyclops
Midnighter - Punisher
Martian Manhunter - Wasp
Cyborg - Black Widow
Firestorm - Human Torch
Black Canary - Storm
Catwoman - Elektra
Doctor Fate - Iron Fist
Vixen - Black Panther
Fairchild - Luke Cage
Constantine - Doctor Strange
Steel - War Machine
Red Tornado - Vision
Zatanna - Scarlet Witch


Villains

Lex Luthor - Iron Monger (Zeke)
Darkseid - Apocalypse
Circe - Doctor Doom
Joker - Bullseye
Prometheus - Taskmaster
Ras Al Ghul - Baron Zemo
Poison Ivy - Madame Masque
Deathstroke - Red Hulk
Captain Cold - Magneto
Mirror Master - Mysterio
Doomsday - Juggernaut
Bane - Sabretooth
Brainiac - Ultron
Black Manta - Mister Sinister
Arkillo - Venom
Sinestro - Thanos
Parasite - Moonstone
Ares - Loki
Reverse Flash - Living Laser
Conduit - Scorpion (Marvel Version)
Ocean Master - Steel Serpent
General Zod - Leader
Penguin - Kingpin


I don't expect all of these matchups to take place but if even a fraction do, I'll be sated.