I'm not necessarily the biggest fan of a lot of the Christian service organizations that are out there, because I feel that they often let their values override their desire to provide meaningful services. One exception though, is the YMCA. I've belonged to 3 different YMCAs in my lifetime, and I genuinely feel that the YMCA is committed to doing good work while keeping its religious agenda mostly to itself. (Speak up in the comments if you have had a different experience.)
If you are considering joining a local gym, as part of your New Year's Resolution or part of your wedding weight loss goals, consider your local YMCA. I joined ours because it had a pool and was $25 less than all of the other gyms in the area. Our YMCA also had no joining fee and no year-long commitment required. Both the Ann Arbor YMCA and this YMCA have a "young person" rate that is lower than their standard rate - although the age of a "young person" is lower in Baltimore than Ann Arbor. I also like that if I'm going to join a gym and not get the full value of my membership, the money goes back into my local community.
I attended YMCA summer camps and took swimming lessons there for many years. I've always thought that they were an extremely valuable part of my growing up, even the negative experiences I had. I can now right a capsized canoe in deep water. Or swim to safety - the choice is up to me. I like that the Y is committed to helping people who do not have a lot of money reach for and maintain a healthy lifestyle. The fact that a lot of Ys can be found in lower-income areas where there are no other gyms; as well as the fact that they provide childcare while their parents work out; and the fact that they offer financial assistance to low-income persons is a start to helping blur the stark barriers between income and obesity that are very common.
So if you are looking into a gym membership, consider your local Y. They may not be as fancy as some of those $75 a month gyms, but they do good work and may be a much more affordable option if you don't want a long-term contract or feel that towel service is excessive. (Although the Y in Ann Arbor did have towel service.)