I use a Berlin classic, and a reef devil. The berlin is great, as long as you have a large enough pump. The reef devil rocks, as with the berlin it has to be cleaned often, and again pump size is very important. I have used several other skimmers in the past, and these two are by far my favorite for a medium to small tank of course, my largest system is only about 100 gallons, and there are a ton of larger skimmers out there. Both are also moderately priced, and both need a sump. HTH