Price range makes a big difference when recommending a skimmer, although IMO higher priced skimmers don't necessarily produce better bubbles, but they may be easier to dial in and operate, etc. Protein skimmers have a much larger variation in their prices than they do in their ability to remove organics from aquarium water. I wouldn't get the cheapest nor would I get the most expensive. First narrow them down to the size and footprint that you need and those that will fit in your sump. The newer ones tend to claim that being conical shaped with bubble plates are must-haves. Of course, they should all have needle wheel impellers. Long story short, get one that suits your needs and has features you like. Don't worry if something else will make better or more bubbles. It's been documented that they're all pretty much the same at removing organics, except for the really cheap ones.