The Moscow Metropolitain does not compare to anything I have ever seen in America, including NYC (although the efficiency there does come closer than chicago or san francisco). It goes everywhere you could possibly want it to go, it's FAST (as in trains seem to come at maximum every 2-3 minutes, and sometimes just one after the other every minute during rush hour. I can't vouch for the late night trains yet though.
So not only is the moscow metro efficient, easy to get around and fast, but it's clean and beautiful!! It's also very busy. In this respect NYC does not compare at all. The NYC metro, even during rush hour looks like a sunday morning compared to the number of people who ride the moscow metro during the day.
Of course I can only speak for the metro stations to which I have been. But I've only been here a month so far.

Links
>>The moscow metro today
>>Another Fabulous site about the metro in moscow

This is the metro station at Izmailovsky park.

Another view of the above station.

I think this is Kurskaya but I'm not 100% sure.

Many of the stations have connections to other lines by menas of bridges and tunnels under ground. This is one such connection.

This is novoslobodskaya, my stop to go home.

Novoskobodskaya.

Kurskaya again I believe.

An entrance to one of the transfer tunnels (perexod), at Kurskaya (I think)


Moscow is filled with stray dogs.


The dogs here also know the metro system better than myself. They know where to get on and off, and of course have no qualms about taking a seat. (Photo credit to Tyler)