Been rather a while. I need to set a regular time for this or something.
City of Heroes is now well past 6 months and shows no signs of abating. My "main" (the character I play most often), Thermocline, is now level 40, with just under 500 hours of playtime (I think, might be just under 400, I was tired when I was checking).
I basically have a part-time job worth of play in this game. It works out really well from a cost-per-hour perspective. For $15 a month, I get a hundred hours or so of playtime -- that's about 15 cents an hour. Compare with $8.00 for a two-hour movie, or $2.25 for a comic book that lasts perhaps 10 minutes.
Of course, to enable that low cost, I do need to have an internet connection, which has a cost. And a computer. But I used those things for other purposes. Besides, the real comparison I wanted to make was with other games. I'm getting really good value for my money comparing CoH with, say, Half-Life 2. HL2 is a great game, and will probably take me 40 hours to finish. So it'll have cost me about a buck an hour. If I replay it, or play it online, that'll be extended... but for every half-life, there is a Pirates of the Caribbean (cost, $40, actual playtime, about an hour, total time including install and reading manual maybe 90 minutes, time spent enjoying it 0 minutes). That was an expensive one.
So the point is... MMOs are a great value for the consumer, if you play them. If you don't play them, of course, then you should stop paying for them.