To stay good friends or to try for more?

I don't need to be rescued, nor will I die of broken heart :D. However, I'd appreciate to know your opinion.

The story goes like this:

I've get to know a girl about 5-6 years ago. It was not a love-on-first-sight nor anything in that manner, more like a beginning of what gradually lead to a really good friendship. As some things in life changed (we both moved, and such...), we got the chance to spend much more time together and get even closer. So our friendship lead to romantic relation.

To cut the story short, in last 5 years, we were together some time, then we broke up (still remained good friends), then again got together, until we broke up again and remained (a very close) friends. We were together as a couple for about half the time of those 5 years.

The reason for breakup was mostly her feeling of obligation, which I saw doesn't go well with her free-spirited nature. Both of our breakups were suggested by her, and haven't been caused by a major fight or anything like that.

As things are now, we still hang out (on almost daily basis), discuss and help each other with everyday life, and so on.
I want to make a clear statement here that I don't feel lonely nor emotionaly threatened without her around. Sex is also not the issue here (I can find that elsewhere :) ).
Still, I often can't help feeling that a love relationship is a natural next step that is to occur with time. I also sometimes see her discrete signs that she still likes me, sometimes even misses me (Small things, but I really dont think I misunderstood any of them). Not to be one-sided here, even one of our common friends thinks so.

I wouldn't mind at all if we get together again, but not if that would threaten our long-time good relations. Now, I'm not sure if I should try to kill all my affection for her, ignore all those signs I get, try to keep it on "just friends", and date other girls. Or, should I give it some time for things to settle down, and then see if we can get closer?

Please excuse my bad English, and thanks in advance for your comments :).

I'm in the same situation... almost parallel to the events you mentioned and your relationship with her... I have no idea what to do as well... -_- Good luck is all i can say... if you love her, you'll be persistent i guess, but if you don't mind losing her.. I'd say find someone else.