Many times my fellow Christian friends who are not familiar with the LDS culture are a bit turned off by how the LDS church assigns people geographically to their congregation. I usually see them looking for a church that they like and that fits in well with their interests.
While people are not forced to attend the congregation (the LDS call them wards) that is in their location, it is highly encouraged.
For those who have complained about being assigned to wards, the Japan earthquake shows an example of where being assigned to a ward can be very beneficial and inspired. During the earthquake in Japan, the LDS church was able to take account of the members of all congregations within the country in a matter of hours, which impressed someone over at MSNBC. Read more about it at this site: “In Japan Mormon network gathers the flock.”