VLC will play them, but it doesn't support all audio codecs used in 3gp (notably samr). You can try and find out whether it works though. You can also try QuickTime Alternative (don't know if it'll give you more stability, because a lot of the files are QuickTime files anyway - in particular the audio and video decoders). Last you can try a combo of ffdshow-tryouts along with a 3gp splitter (like Haali - it parses mp4's mov's and 3gp's). Don't know if it'll play the odd audio portions either.
If none of those prove suitable, you can try converting your 3gp files in the interim. Google for some (lots of freeware ones - here's one hit:
http://www.gromkov.com/faq/faq2004-0067.html ).
I'm really shocked something as... non-essential as QuickTime Player would cause a BSOD. Does it only happen with 3g2 files? Does it happen with any other container? (mov, mp4)