The 4 I'm currently using:
Original CM Storm Sniper, had to paint the inside black myself and purchase the clear side panel separately when it became available, I had made my own until then. Great case, love the handles, the fan controller, and most importantly the look, nothing else comes close. This is my main rig outfitted with an Hexacore i7 and GTX970.
Next is my CM HAF 932, this one came painted black on the inside and with a clear side panel. This is my server outfitted with 10 drives ATM, ready for another 4 easily. i7 920 powered, very quiet.
Then there's my SG10, excellent mATX case, so far the best I've ever worked with. Plenty of room for big video cards and large tower style coolers. Currently I have an i7 960 with a Silver Arrow cooling it with an HD7950, I swap in the 970 when I don't feel like lugging my sniper to Lan parties.
Last is my HTPC Fractal Node, nice little case, easy to work in, room for surprising amount of drives and room for a full sized GPU.
I also have a Corsair 250D which was another great little case, I have plans for it, just going to wait until I need to upgrade something, which I don't see being required any time soon.