Puzzle

 ACROSS



  1 Up, in baseball

  6 "This Is Us" network

  9 "You ___ thing!"

 13 Casual goodbye

 14 App that lets you rate drivers

 15 Clearasil target

 16 "Whose Line Is It Anyway?" regular (starts with Batman's alter ego)

 18 "Now, doctor!"

 19 "Evil Woman" band, for short

 20 Keats wrote one to autumn

 21 "Pong" maker

 22 Advanced, financially

 24 What sycophants do (Aquaman)

 27 Gap

 29 All the rage

 30 Bora Bora, par exemple

 31 Wilbur's human friend

 32 Acted like

 34 Farm bundle

 35 Golden Flashes' Ohio school (Superman)

 38 Decomposes

 41 The "E" in QED

 42 Words after a guess

 45 Where the Alps are: Abbr.

 46 ___-disant (so-called)

 47 Clara Bow nickname, with "The"

 49 In one's birthday suit (Iron Man)

 53 Stuffing seasoning

 54 "Likewise"

 55 Every last bit

 56 More, in Madrid

 57 In ___ of

 58 Best-selling writers? (Spider-Man)

 62 Menu with a Copy command

 63 Charity

 64 What the first letters of this puzzle's superheroes aptly spell

 65 Gillibrand and Warren: Abbr.

 66 Class-conscious org.?

 67 ___-Roman

DOWN

  1 Too

  2 Bit of reading for a fortune-teller

  3 Singer also known as Sasha Fierce

  4 Author Rand

  5 ___ Bo

  6 Hawk or Raptor, briefly

  7 Hospital unit

  8 React to an onion

  9 High-carb salad type

 10 Mark Antony's fourth wife

 11 Winning again and again

 12 One may move to a warmer climate

 14 Language of Lahore

 17 ___ Raton, Florida

 21 Astern

 23 Istanbul residents

 25 Fictional Butler

 26 Sci-fi syntax snubber

 28 U-turn from SSW

 32 Courtyards

 33 Pro bono TV spot

 34 Polar bears' perches, for short

 36 Advertising sign

 37 "Sesame Street" watcher

 38 Flippers' transactions

 39 Enjoying nature

 40 Exchange, as an old car

 43 Cat native to Thailand

 44 Kind of chemistry

 46 Schuss, e.g.

 47 Doing nothing

 48 To a smaller degree

 50 Licks

 51 Cosmic destiny

 52 The "E" of BPOE

 58 Gold miner's vessel

 59 Sometimes-creamy quaff

 60 "Notorious" justice, familiarly

 61 ___ for the course

Solution