I like subs. However, they can produce more room modes, and that sounds horrible. Therefore I would advice to go for multiple smaller subs (at least two and perhaps four, if you can find locations for them), plus room equalization like the DSpeaker Antimode 8033. See here for some introduction:
http://www.acousticfrontiers.com/20101029using-multiple-subwoofers-to-improve-bass-the-welti-devanti...
http://www.theabsolutesound.com/articles/dspeaker-anti-mode-8033-dsp-subwoofer-equalizer-tas-204/
http://www.acousticfrontiers.com/20101029using-multiple-subwoofers-to-improve-bass-the-welti-devanti...
http://www.theabsolutesound.com/articles/dspeaker-anti-mode-8033-dsp-subwoofer-equalizer-tas-204/