Nominate best game series ever

I'm going to use the answers to this thread to form a poll which hopefully will get a sticky or something and we can find out what people think is the best game series of all time.

And yes, Halo would be a series. It doesn't have to be a long list of games for it to be a series, they just have to be related(for example, the Halo series is just as much a series as Final Fantasy.)