If I had to place them in order from most important to least important, I'd say:
Feed the poor
Build a mosque / Education / Islamic Governance
Every area is different, so it would depend on location. Some locations may not have a big Muslim community, so setting up a mosque may be at the top of the list just for the sake of trying to establish a Muslim presence in the area so other Muslims (and even non Muslims) may get involved. In places where there are lots of Muslims, mosques may already be common. In a non Muslim country, mosque, education, and even "governance", tend to go hand in hand most of the time. In my area anyways, they are sometimes set up as a community center, Islamic school, and a place to send zakat / sadaqa. Also, a house or even an open area outdoors could be used as a mosque where people can gather to pray, give dawah, or provide education.
I ranked feeding and taking care of the less fortunate at the top because if you think about it, some people are in that situation due to unseen circumstances (loss of job, house destroyed, etc.). By helping these people get back on their feet, hopefully they 'pay it forward' and join the cause to help others as well. That's speaking on a local level. If we're talking about worldwide, there are some countries where there is no infrastructure or functioning government left. These places have to rely on outside help to get them the resources they need.