The REL seems to be a big favorite on the Maggie forum over at AA. The ACI Titan get's mentioned often along with the Vandersteen.
I've personally never heard any of them, so I'm not making an endorsement.
Many here seem to like the VMPS, but of course, they require an outboard x0ver and amp.
I've got a Mirage that I was using with my modded 2c's. It's ok, but there's definitely better to be had. I bought on a whim. Since I changed speaker cable, I don't feel like I really need a sub now.