In Sucker Punch, Baby Doll's reality is that she has been unfairly institutionalized by her stepfather. But in her mind, she transports herself to a world where instead of an institution, she is sold into a brothel/nightclub but at least has the friendship of her fellow dancers/inmates. Even within that world, she must escape further into her mind as she dances - this time into a world of action and adventure, swords and machine guns.
In Inception, Cobb's reality is that he is a thief with the job of stealing ideas from the minds of others. Though he explores the minds of others, his own serves as a prison. The internal worlds Cobb explores and creates are mutable and treacherous and at times, indistinguishable from reality.
In both films, the passage of time is greatly affected by how deeply you delve into the mind. Both have jaw-dropping special effects. Neither have what I would call a "Happy Ending." And yet, I not only enjoyed them both but they tickled my mind and imagination in a way that was both uncomfortable and stimulating.