Personally I download only MP3s and bring them in to iTunes from my PC in order to maintain my ability to easily cut ties with the iTunes eco-system (not as convenient - but better) Regarding Apps - I just try to never purchase them. Although irritating it is relatively easy to keep dependencies on any one company light and integrate data where it matters - mail/calendars etc..

For me a bigger bug-bear is is being shoe horned in to specific options; for example Apple's maps update - where I can no longer use the far superior Google Maps App - as it is convenient for Apple's business strategy - this has seriously pissed me off.