Ya, video games are one of the best cost-entertainment ratio things out there; beating out most table top games (maybe not board games but that's arguable), assuming you get the 'right' game.
Friend playing WoW, considering he pays $15/month + 65 for the original game + 65/expansion every 2 years, the hours he has put in (actually, the weeks of real time) he has put in, makes that ratio like pennies/hour of entertainment.
A meal out costs maybe $40, movies $15/ticket, etc...so you can't get entertainment for 0.01/hour unless you stay home.
With how much I played Quake 2 and Quake 3 CTF, etc back in the day, easily a penny/hour or less adn even with StarCraft 2 now, hourly cost ratio is nothing (also, got StarCraft 2 for free due to a trade in, so even better).
D&D also has a better cost to time ratio since you technically just need a few books and can use those forever if your group doesn't want to switch rulesets.
Sanjay