I was on the NuvaRing for nearly a year, with no noticeable side effects. I only decided to switch to something else because one time it FELL OUT!! How could I not have noticed this happening?? I didn't realize it wasn't there until I started bleeding all over the place unexpectedly. That was a really close call; I'm glad I didn't get pregnant.
FYI, I'd been on "the patch" before NuvaRing, and didn't like how that upset my stomach on a regular basis. That's why I switched to the NuvaRing, and didn't have any stomach troubles with it.
After the NuvaRing fell out, I got a Mirena IUD. That thing is causing the worst side effects, and I wouldn't recommend it to anyone. I'm not sure what the best birth control option would be now; I'm kinda' ready to be done with hormones for awhile.