My place is close to Karl Johans gate, Solli plass, Akerbrygge, everything is nearby and a walking distance, no need to take a bus or a tram. The apartment is good for couples, solo adventurers, business travelers, and families (with kids). The price is low so you can spend money on other fun stuff in Oslo.
Livingroom: a sofabed (2 person)
Livingroom: airmatress (2 children/small persons)
Bedroom: a double bed (2 person)
1 min walking to public transport
7 min walking to the airport train.