A borrowed the dvds of Dead Like Me, and I have made it through series one and begun series two. It's absolutely brilliant.
The setup is half Wonderfalls and half Tru Calling, with a touch of Good Vs Evil.
A young woman is tragically killed by a falling toilet seat and then finds herself not dead but undead, and now a grim reaper - releasing the souls of those about to die.
It ends up being a lot about working, as well as death. Her reaper duties are unpaid, so she needs a day job as well. The series also follows what happens to her family after her death. It's black humour, mostly - the little demon guys who set up the actual deaths are like out of control practical jokers - but there's always the underlying seriousness of the deaths.
The series has an excellent cast, and excellent characters. The deepest are the other reapers, and they're all fascinating characters (some of them seem pretty shallow when you first meet them, but that doesn't last long).
In the episodes I have seen, the only weak one was a flashback (i.e. "just reuse some old footage") episode. Even that had a good plot in between the recycling, it was just annoying to have to rewatch the old bits to get there.