The coralife skimmer... some people swear by them, others don't. They have a lot of quirks.... lots of folks have trouble keeping them running correctly. Microbubbles seem to be a recurring problem with them.
I'd stay away from the Red Sea (berlin) skimmers. I've owned two of them and have since relegated them to "shelf duty." They are nearly impossible to properly clean and are terribly inefficient.
I've got a very high end skimmer that I love, but I've also got a couple of Octopus skimmers that I believe are a tremendous value... they perform outstanding for their cost. Lots of folks here can probably chime in on other skimmers that offer similar cost-performance compromises.