IMO the best bang for the buck if you are using the Oceanrunner pump. This is the original recirc skimmer.
Make sure you use the feed water to adjust the skimmer water level and toss the adjusters on the outflow.
Pros:
Skimate Production
Well build
Easy to use (no fiddling once it is set up)
Price
Cons:
Footprint is big
Level adjustment valves on the outflow are useless