Share 'Best tubes to use with clinchers'

I know, I know - the ONLY thing to run in cross are tubulars, but for those of us who only have one clincher wheelset, does anyone have a good recommendation on tubes? I've been using Q-Tubes and I've had nothing but bad luck with them. I've flatted more this summer than I have the last two years and it always seems to be the valve stem area that's to blame. In fact, I've had a similar experience…