ALL ALLIANCE PLAYERS, if you play the game right.

Top tier on any of the 6 US based alliance players gives you lounge access alliance wide, except domestic US when flying on a purely domestic itinerary.

Most (all?) international top tiers on alliance members give you lounge access alliance wide without a domestic US exclusion.

So, AA EXP gives me:
- Lounge access anytime on the day I am traveling internationally at any Oneworld Lounge, including AA Admirals Clubs.
*AA PLT - OneWorld Sapphire - gives access to all business class lounges; AA EXP -Oneworld Emerald - gives access to First lounges as well where they exist. This includes the nicest lounges in the world, CX's F lounges in HKG - when flying CX (or any Oneworld carrier) in coach.

BA Gold (Oneworld Emerald) is the same, except US domestic itineraries are not excluded. So I get lounge access when flying AA domestically on coach fares, in F 90% of the time with free AA EXP upgrades, and free lounge access at the same time with my BA Gold (Oneworld Emerald) card.

Same with Star Alliance:
BMI Gold (Star gold) gives me lounge access alliance wide, including UA and US domestic on any fare.
Without BMI Gold, I would already have lounge access as a 1K if flying international on any fare.

Same with Skyteam....I am surprised someone as well posted as you would not know this.