Theme: Big Game - not really about the game, just words that start with a B and G.
17A. Nonconformist Harley-riding groups: BIKER GANGS
25A. Rose and Orange: BOWL GAMES
38A. Places where critters procreate: BREEDING GROUNDS
46A. Honey Ryder and Mary Goodnight: BOND GIRLS
59A. Barry, Robin and Maurice Gibb ... and a hint to 17-, 25-, 38- and 46-Across: THE BEE GEES
Argyle here. A debut from this constructor but there may be more in the near future.
Across:
1. Closest pal, in IM shorthand: BFF. (Best Friend Forever)
4. Fish-eating raptor: OSPREY
10. Wretched: VILE
14. Period of history: ERA
15. Put a new flannel layer in, as a coat: RELINE
16. Fruit punches: ADEs
19. Picky details: NITS
20. Chief Norse god: ODIN
21. "Hulk" director Lee: ANG
22. Photoshop creator: ADOBE
23. Longtime "SNL" announcer Don: PARDO
28. Hoppy brews, for short: IPAs. (India pale ale)
30. Dog command: HEEL
31. Shake, as with fear: QUAVER
34. Demeanor: MIEN
35. "__ on a Grecian Urn": ODE
41. Camera initials: SLR. (single-lens reflex)
42. 35-Across, e.g.: POEM
43. Gulf War reporter Peter: ARNETT
44. CancĂșn house: CASA
45. Quick cash sources, initially: ATMs. (automated teller machine)
50. "Fantastic!": "SUPER!"
54. Like beer in a cooler: ON ICE
55. Unit of resistance: OHM
57. Lost fish in a Pixar film: NEMO
58. Letter before eta: ZETA
62. Rowing tools: OARS
63. Pine secretions: RESINS
64. Antonym of post-: PRE
65. Gin fizz fruit: SLOE
66. Remove, as a chin strap: UNSNAP
67. The "S" in iOS: Abbr.: SYS. (Internet (i) and operating system)
Down:
1. Jazz style: BEBOP
2. Mexican artist Kahlo: FRIDA. Self-taught painter (1907-1954) Wiki
3. Fire-walking mystic: FAKIR
4. Bruin legend Bobby: ORR
5. Nintendo rival: SEGA
6. Backup strategies: PLAN B's
7. Drummer Starr: RINGO
8. London's land: Abbr.: ENG. (England)
9. "Okay": "YES"
10. Graffiti creator, perhaps: VANDAL
11. Figure of speech: IDIOM
12. Do not disturb: LET BE
13. Letters before tees: ESSES
18. Curly salad green: ENDIVE
22. Child psychologists' benchmarks: AGE NORMS
24. Where to find columns with views: OP-ED PAGE
26. Millard Fillmore, partywise: WHIG
27. Ogle: LEER AT
29. Melodic passages: ARIOSI. Italian
31. NFL play callers: QBs. (quarterback)
32. Internet address: URL. (Uniform Resource Locator)
33. __ Lingus: Irish carrier: AER
34. Roaring-lion studio: MGM. (Metro-Goldwyn-Mayer)
35. Washington's bill: ONE
36. Banned pesticide: DDT. (Dichlorodiphenyltrichloroethane)
37. Winter hrs. in most of Michigan: EST. (Eastern Standard Time)
39. Not far: NEAR
40. Like heroes deserving more recognition: UNSUNG
44. Jewel box: CD CASE
45. Hearth receptacle: ASH BIN
46. Obnoxious clowns: BOZOS
47. Basketball's Shaq: O'NEAL
48. Part of TNT: NITRO
49. Rich soil: LOESS
51. Pals, in slang: PEEPS
52. Nail-filing board: EMERY
53. Kentucky Derby flowers: ROSES
56. "American Beauty" actress Suvari: MENA
59. __TV: Turner channel: TRU
60. Farm layer: HEN
61. Telepathy, e.g.: ESP. (Extrasensory perception)
Argyle