I've also tried expensive cables.
Well, they were expensive to me, that is. I could never justify spending over $15 - $20 a foot. To some, that's horribly expensive. To others, incredibly cheap.
I've gone through several system changes that involved different components that were more money than what it replaced and less money than what it replaced. Yep, you read that right - the change was not always a "price increase = upgrade" change.
And I have finally ended ended up with the perfect speaker wire for my system - Monster. I know they have a bad rep to some but... what can I do?
Now, I believe it's all about system matching. Once you find that combo, you're set. When I first tried the Monster, they sounded good but I wanted something more. So I tried other stuff which was good initially but I eventually discovered something "lacking" or there was something missing. Eventually going back to the monster stuff, I realized that my system could not do "everything" since there are many types of music* but what it does do, is impressive.
* Ever hear a pair of speakers that were GREAT on jazz but poor on rock? I have....
Anyway.... system matching. That includes interconnects, speaker wire, amp, speakers... and even the room!