Shinagawa-ku is a practical ward built around airport and Shinagawa access. The Yamanote and Osaki side is good for Gotanda, Osaki, and Meguro, giving office mobility without leaving the west or south side; the Shinagawa and Keikyu side matters when Shinkansen, Haneda, or south-side travel is involved; and the Oimachi and Tokyu side keeps practical shopping, local streets, and calmer residential options open. Shinagawa, Gotanda, Osaki, and Oimachi are all useful for trains, airport access, and work.
Gotanda and Osaki are practical, though the street feeling changes quickly depending on the exit and the river side, while Oimachi keeps trains, shopping, and daily errands together without relying only on Shinagawa Station, and Togoshi and Hatanodai are stronger for local streets and calm than for airport-name recognition. Choose the ward for its mobility first, then judge daily life station by station, comparing Minato, Meguro, and Chuo-side choices before deciding.