The first time I watched Inception I found the tone, rhythm, pace, and style extraordinarily similar to Lost. The story was revealed layer by layer, and sometimes you weren't sure if what you were seeing was real or a dream (like Hurley in the episode "Dave"). Now that I've watched it three times, I have found some more surface-level parallels between the two:
The most significant turning point occurred on a flight from Sydney to LAX.
On said flight, there were several instances in Inception when a character "woke up" dazed and confused, just like in Season 6's "LA X" when Jack "woke up" on the flight and seemed initially very confused. Similarly, Inception emphasized several moments when a character woke up "down there," in a dream, confused and finding his bearings in a whole separate universe--similar to when Jack woke up on the island, which was almost like another reality.
Time refraction: On the Island, time was skewed so that the doctor from the Kahana washed up dead onshore "before" he died on the boat. Some have theorized that time moves more slowly or more quickly on the island (rather than moving at the same speed, just offset from normal time). This is similar to when the van in Inception was falling into the river continuously.
The "closed loop" concept: Arthur and Ariadne made Escher-esque closed-loop paradoxes to surround the edges of their dreams, almost like the island was inescapably surrounded by paradoxical forces. And the Buddhist concept of escaping the endless cycles plays heavily in Lost.
Towards the end, you think you know that this world is real but it turns out it may be just another level of reality or something that happened after everyone died.