Indiana and USC have had great bricks and mortar MPA programs for a long time that always rank high in the US News and World Report grad rankings. Undoutably their online MPAs will be well worth it. UNC also has a good reputation. If you are still looking for other online MPAs beyond these 3 Colorado-Denver and Nebraska-Omaha are respectable.
Getting an online MPA from Indiana or USC while working in a public admin/policy related job could be of a great benefit to a student compared to only studying. You can cover the costs while still working, Moreover, an MPA is an applied, professional degree in the end. I studied for my MPA mid-career. My wife, and other friends, studied directly or shortly after their BAs. The difference? I knew why I was studying each and every course and could apply what I learned the next day at work. The downside? It will take you probably 4 years to complete the degree. But, in the end, a career is a marathon so I wouldn't worry about it.
Personally, if I had a choice between going to ANY top public admin/policy school full-time OR going to Indiana/USC part-time online while maintaining employment I would take the 2nd in a heartbeat - employers are always looking at high quality experience that is coupled with academic credentials - something schools won't be able to tell you!