QTCurve is great for flat styles but it has menu shadows and they are not removable from any option in the configuration interface, my solution was to patch qtcurve to remove shadows. I patched both versions of qtcurve(for KDE4 and GTK+2). Due to GTK+3 API being so stable I couldn’t get it built because it was not released yesterday.
Download latest KDE4 and GTK+2 versions of qtcurve from below.
Apply these patches.
And compile qtcurve and then apply the following theme.
This theme is based on,
http://lgsalvati.deviantart.com/art/Full-Flat-Plasma-theme-327496724 by lgsalvati