Guitar.com: What brand and gauge of strings are you using?

King: D'Addario. I use different gauges, depending on the tuning. For D#, I use .009-.042. For C#, I use .010-.046 and if we drop-D, I put a .056 on the bottom, instead of the .046.

Used on Orchid and Morningrise, before switching to 10's on My Arms Your Hearse and onward.

Used for C'est Chic, particularly on "Le Freak", as stated by this February 3, 2020 Guitar World article.

The Neve console’s 31102 mic preamp/EQ channel strip generously reduces bass (to provide extra room for Bernard Edwards’ booty-shaking bass low-end thump), while a miked Deluxe Reverb recorded simultaneously on a second track mixed below the direct track preserves body.

(...) Original gear

Guitar: 1960 Fender Stratocaster with maple 1959 neck and hardtail bridge (neck pickup only), Master Volume: 10, Neck Tone: 10

Direct input: Neve 8068 console with 31102 channel strips (Mic Preamp Level: -30dB, High Frequency: 12kHz, HF Level: +6dB, Mid Frequency: 4.8kHz, MF level: +4dB, Hi Q: On, Low Frequency: 220Hz, LF Level: -6dB, High Pass Filter: 160Hz, Low Pass Filter: off)

Amp: c. 1968-77 Fender Deluxe Reverb (Normal Channel input 1, Volume: 4, Treble: 7, Bass: 5) with Oxford 12K5 12-inch speaker

Effects (outboard): Neve 33609 compressor (settings unknown), Pultec EQP 1A3 2-Band EQ (settings unknown)

Strings/Tuning: D’Addario XL120 .009-.042/Standard

Pick: Fender Thin

A user-uploaded photo of Jeff Hanneman's rig diagram shows he uses D'Addario EXL120 Nickelwound Guitar Strings (9-42), likely for tuning in E flat/D#.

In the article and the video, Scott says he switched back to using D'Addario 9-42 for standard tuning, as that's what he says in used back in the 80s.

In a Premier Guitar Rig Rundown featured on BraveWords, Russ Parrish, also known as Satchel from Steel Panther, discusses using D'Addario EXL120 Nickelwound Guitar Strings (9-42) for his setup.

According to Premier Guitar 2021 interview with James, he uses D'Addario 9-42 EXL120 string set. This set is signficantly lighter than James' previous gauges. James describes the switch to lighter gauge as follows:

Opting for a slim neck is just one of the ways James has adapted his rig to his carpal tunnel issues. He's also switched to lighter string gauges. "It's helped a lot," he says. "I broke strings a lot in the old days. Before I had a guitar tech, I had to use .011s so I would make it through the show. I went down to .010s for a long time. This tour, we went down to .009s, and it's been incredible—the ease of playing. I went to extra-light gauge on the acoustic, too. I also try to limber up and do stretches. I hope I don't have to have surgery. And I have braces I wear when I sleep."

You can see Mikio talking about strings in this video: https://www.youtube.com/watch?v=s4OZEc20DBg

On his official website, Jim Campilongo says, "D'Addario EXL120 strings for the Tele..."

Serge Tabachnikov, known for previously using Ernie Ball, Dunlop, and Rotosound strings in calibers 10-46 and 10-52, now prefers D'Addario EXL120 Nickelwound Guitar Strings in 9-42 gauge. In his YouTube video titled "Распаковка посылки от D'Addario," he shares that these lighter strings offer him greater comfort, despite his earlier reservations about using 9-gauge strings.

In the YouTube video "Questions Meet Answering" by 331Erock, Erock mentions using D'Addario EXL120 Nickelwound Guitar Strings (9-42) on all his guitars.

He prefers either Ernie Ball Super Slinky [.009–.042] or D’Addario EXL 120 [.009–.042] strings, and his picks are Fender 351 medium celluloid.