MindMeister

MindMeister is a great fit for small teams that do a lot of brainstorming, planning, or strategy work together and want a visual way to organize ideas.

At $7.50 per user per month, the Personal plan gives you solid real-time collaboration and the ability to connect your maps to MeisterTask for follow-up actions. The big downside is the free plan limits you to just 3 mind maps, which runs out fast, so most real users will need to pay.