Bob , are you using a brick wall limiter? Like Voxengo Elephant, concrete limiter, FXG , Waves L2 ,Ozone limiter ,the list goes on and on. These will raise your levels with out clipping and make them extremely loud , now whether they sound better is anther story.  You may be asking something complete different but compression and limiting is the way to make things louder. 

Waves L-316! It will squash it to death! LOL  Sometimes waves will put it on sale. L-2 is also really good. I don't like L3  much.  Any Voxengo plugins are real bargains!  Dave Brown has a nice limiter too.  Sony Oxford Limiter is ok but I think its a little over priced.  I like Fabfilter stuff too they make Pro-L that is a very popular "Mastering" type limiter.
 

Wow! You guys have really given me a lot of good material to think about. And, I must say, that I got something new out of every single reply that all of you made. I don't know how I could possibly thank each one of you but know this: I will now produce something much better because of all of your efforts. Sometimes  the best we can get is a thank you although it sounds as if I am a jerk this way. Maybe its the karma thing for all of you?
Anyway, reading through all this, which I have done several times already, I feel like I am reading an insider's secret guide to better production or something. I must admit that I was unable to follow some of the wisdom at this point but most of it I got. I bet some of you guys are some heavy-duty producers and just aren't saying so.
Unfortunately it would take longer than I have to respond to what each of you has said, but I promise you that I got something new to think about out of each response so thank you all again!
If there are others still who wish to impart even more wisdom I would like to encourage you to do so if you have the time. I assure you all, your efforts are not wasted and I will keep coming back to this thread in hopes that there is even more advice to read.
 
Thanks Thanks Thanks!!!
 
bob

+1... great stuff here... thanks all
 

As I have said before and will say again...BOOST!! to WIN! -S

BOOST11 I mean!
 

Both the (Nomad Factory) BT Brickwall, and LP64 Multiband, as well as Boost 11 will give you good results. 
And then there is the Concrete Limiter (Pro channel) as well.

When you say clipping..  what exactly do you mean?
 
There's good ol' analogue clipping where the peak tries to go higher than the power supply will allow and rounds off.
Or tube clipping where the peak saturates the plates and rounds off.
Digital clipping where you hit the biggest number and the peak squares off (or worse, wraps around to 0 and starts again)
Then there's limiters, where the peaks are artificially clipped, but it's still clipping all the same and is distortion just like any other clipping.
 
If you're trying to raise "loudness" by simply hitting a limiter hard the clipping (distortion) will create high harmonics (sparkle/presence/air) which for the right genre of music could be a good thing...  and thus why your test audience prefers it over the quieter version.

I noticed Mark Ronson clipped Amy Winehouse material.
Seems to be the way of the world.

Beware of such, the right combination of clipping and power can blow a nice set of speakers.