I've got a Yakima Kingpin hitch mounted rack that holds 4 bikes, has built-in lock for bikes and a bottle opener. Works awesome. ($50 CL find)

I've got a couple of no-name roof racks that work great though getting the bikes up on the roof of the van is a bit of a pain.

I've got a Yakima universal-mount rack that holds 2 bikes and is very secure. ($10 thrift store find)