I'm happiest with my Travelpro and Atlantic pieces. Atlantic is very solid as it has a one-piece internal frame. Unfortunately, this adds quite a bit to its weight. I bought a large Travelpro for my last trip It held a lot and came with a detatchable garment bag. The garment bag was great for my formal.
We've also found decent pieces at Ross, like an American Airlines pullman that was huge, fairly solid, and only $40.