Stockholm / Goteborg / Oslo
A lot of Sterling routes already had competitors on them: Ryanair, Scandinavian SAS, Norwegian, Easyjet, etc... There's not
soooo many routes than have been left completely unserved with their collapse, except maybe a couple to Biarritz...
Sterling's collapse is a sigh of relief for competitors. I'm not sure to what extent we'll see airlines racing to take on their routes.
All that said, don't forget that Ryanair are (once again) in advanced negotiations with
Copenhagen airport, and correct me if I'm wrong, but isn't there an airport near Uppsala getting ready to become an international airport? That could potentially take Ryanair's fancy.... Maybe, maybe not...