Like most people, I felt the ending to Life on Mars (The US version) was pretty disappointing. So here's my take on it instead.

Sam tells the voice over the phone that he likes it in 1973 and he doesn't want to leave. He hangs up. Scene cuts to a bald man sitting alone in a basement. He has a phone and a clipboard in front of him. The man shakily hangs up the phone and picks up his clipboard. On it are a list of names and dates, each name crossed out, all except for Sam's. He crosses out Sam's name and writes under it.. "Now what?," a question to himself now that his list has come to an end.

Cut back to Sam, he confronts Annie and they kiss.. end of story.