Board Thread:Questions and Answers/@comment-73.193.12.221-20150528130934/@comment-2600:100E:B113:50DC:25F4:C988:C5F0:DAFF-20171019205525

These are both pretty obvious, but I didn't see them mentioned above:

3* Hulk, 3* Black Widow, 3* Scarlet Witch

(Hulk and Switch have passives that help charge Black Widow's Green.)

3* Iron Man, 3* She-Hulk, 2* Storm

(Iron Man's Yellow charges 2 AoE attacks and a decent Green.)