most effective bass traps

Thanks for all the responses thus far. I have seen the data on the Real Traps and other websites. It's difficult for me to view the data as objective since I have no direct knowlege of the subject and the results support the product being advertised. Asthetics is important. Interestingly, I just had my room professionally acoustically treated. The focus was on the upper frequencies. The reason for asking this question is just in case this treatment leaves any low frequency issues unresolved.

Shadorne

As an aside, I enjoy your well thought out responses to many questions on this forum. Am I correct to assume that using corner traps, such as ASC tube traps, is virtually always likely to improve bass response? One nearly always sees them in every high end store/room/show/ etc. in all 4 corners. I have some ASC traps already, and aesthetically these will probably be the best fit for my room.