If you like the sound of Magnaflows, but don't like the price. Look for Jones Max Flow SS mufflers, they are Magnaflow ripoffs made of thick raw stainless steel and sound a little more aggressive, can be had for about $40-$50 bucks for smaller 2.25/2.5" sizes. I bought all mine off of Mandrel Bending Solutions on eBay and they were great to deal with and decent shipping to me all the way in Labrador, Canada (very far out of the way and isolated).
I had a DI/DO 3" Jones with a X-pipe built in for my 2500HD Silverado w/6.0L and it sounded great, mellow at idle but very aggressive when you got on the pedal. I got a lot of power back, but I had exhaust leaks on a dual 3" exhaust with no H or X pipe, so I don't know where the extra power came from exactly.
I recommend them to everyone though, they are cheap, built well (If you don't mind ugly raw stainless, but you can polish it or paint it like I did) and sound great and apparently flow better than Magnaflows, so there is also that.