I've always been a big fan of Altech Lansing:
http://www.altecmm.com/product_cat_s...region=northam
and Bose:
http://www.bose.com/controller?event=VIE...ex.jsp&ck=0
but obviously Bose are much higher quality which means that they are much more expensive but I personally think that Altec Lansing is a great cheaper alternative from personal experience.