Other than flat tires I've never had any real bike trouble on my sturdy mountain bike. My fussy road bikes were another story with constant little adjustments necessary.

Since I put this green slime stuff in the tires I've never had a flat tire. I have been storing my bike outside and I think that is making it get squeaky. The seat creaks, too. But these problems aren't bad enough to me to count as bike trouble, and are largely self-inflicted.