My personal list who i would love to see in oneworld:
1. Aer Lingus
2. Royal Air Maroc
3. Air Tahiti Nui
Hopefully this 3 airlines listed above will join soon.
4. Air Transat
5. Interjet
6. Air Seychelles
7. Bangkok Airways
8. Philippine Airlines
9. Hawaiian Airlines
A few airlines who would fit in oneworld and covering countries like Canada, Thailand or Mexico.