A nice list of common Chinese words here: list of common Chinese words at Pandagator
This list strikes a particular resonance as I know almost all the words on it. Many have been important words I have picked up in the past couple of months.
This tells me that most of these words must be truly high frequency (otherwise I wouldn't know them ;)). It also suggests that the few I don't recognise or have forgotten the tones for are worth assimilating. Nice one Pandagator :)