It's hard to not recommend another Cooler Master if you've loved the one you had. The Storm Scout and Storm Enforcer (here
, and here
) are both good choices from what I've heard. The HAF 922 (here
) is also good. It may not be your tastes, but if you want to go up a little bit, I have been recommending the Azza 9000 (here
) which also comes in white if you do prefer it. If you want to go really flashy there's the NZXT Phantom in red (here
), although I must confess to having heard more about its looks and nto much about its cooling performance.
Edit: Also, like TheBigTroll says, you're better off not wasting money on some of these closed loop systems. In general they aren't much better than much cheaper air-cooling options.