A Winfinite / Tile Destruction Team is best: ProfX, GSBW, SWitch - OR - XFW, Magneto, Loki - OR - Hulk, KK, 2*Storm
A Board Control team could work too: Quicksilver, Star Lord, Switch = Switch generates purple for Sleight of Hand to cover up 3 CD tiles, QS Idle Hands can match CD tiles too
A Retaliation team could work I think: 4*Deadpool, Capt Marvel, OML/Patch = tank with Logan or Marvel to trigger Deadpool, add Strike tiles
An AP Drain Team could work I think: She Hulk, Cho, KK = generate 12 to 18 green to use Furious Charge repeatedly until his Black AP pool is back to 0.
An AP Theft Team could work I think: Hood, Wasp, Iron Fist = add black tiles so that Hood and Wasp always steal Black from Galactus.
An airborne team might work: Nova, Cyclops, IMHB = use IMHB and Cyclops to produce red for Nova to constantly throw Galactus airborne (I believe he can be thrown)
A Bagman team might work! (this would be an epic win if it works): Bagman, Kingpin, Switch = Switch produces Blue and Purple, Kingpin uses Purple to produce Yellow, Bagman uses Yellow to increase countdown tiles, Bagman uses Blue to lock CD tiles. This should stall for a long time so you can kill him with match damage.
What doesn’t work:
Stunning - Galactus is immune to stun
Invisibility - Galactus’ board destruction and AOE will laugh at you
Nick Fury’s Demolition - Galactus does not match tiles
Peggy Carter’s Legendary Presence - does not increase 28 AP Devourer of Worlds power beyond 30 AP
StarLord’s Everyone with Me - does not trigger on Galactus’ passive abilities to generate AP
Dr Strange’s Flames of the Faltine - does not trigger on Galactus’ passive abilities to generate AP