Cryptic Studios for Star Trek Online. Otherwise, my journeys in Guild Wars, Lord of the Rings Online, and the RIFT beta were completely free. We have come a long way from the days of $8/hour CompuServe games, my friends.
Of course, I've had months where I've juggled a couple subscriptions, or purchased a new game, or even (gasp) spent a few bucks on microtransactions. Disposable income is a really nice thing to have, but it seems like there's a lot more to spend it on online than ever before.
Because we're nosy about your finances, how much did you spend on MMOs last month? That's including subscriptions, game purchases, microtransactions and paid services. Don't forget to itemize your purchases for tax deductions!