Met my husband playing an MMORPG. It grew naturally from regular chatting in guild to hanging out and doing random stuff in-game together to feelings. We've been married for over 15 years now.

The trick was that neither of us was looking for romance and treated each other as friends until we gradually came to realize we really liked each other's company more than a friendly amount. I think that's the thing a lot of people get wrong; people get so worried about their love lives that they forget to just treat others as people instead of as potential partners.