IMHO, it would be the Zu Audio Definition MK IV. Read the description of the bass in this review,
http://www.positive-feedback.com/Issue66/zu_definition.htm
I especially like this comment,"A pair of them is barely legal. With the new Def's cabinet structure and loading, these dual 12" drivers will quite literally obliterate anything and everyone in their way. Pressurizing a room to clean dust off walls? No problem." Do read the entire review, as comments are made that the midrange is engaging and treble is silky smooth.
Here is another good review,
http://parttimeaudiophile.com/2012/07/30/caf12-zu-audio/
Since the sensitivity of the speaker is high, the sound will be very dynamic. Also, if you ever decide to upgrade your amp, you won't need mega power, so you could choose a more cost effective high quality, lower wattage amp.
I have heard these speakers at a friend's house with a quality 60 watt amp, and when he puts on the right music and cranks the volume just a little, this is how it feels,
http://www.modrestoration.com/sites/default/files/lc2_maxell_blown_away.jpg