What is "best" for a given setup tends to be quite individual. But here is sort of a "canned" skimmer options answer that I've posted in the past:
If your budget is relatively tight I would consider a beckett style skimmer.
www.myreefcreations.com; http://barraquatic.com; precision marine, etc.... Those are the best "bang for your buck" in terms of raw air injection skimming power. What these skimmers do best is "wet skimming". They do not dry skim all that well, or rather when you do, you tend to end up with a lot of "stuff" in the top of the reaction chamber which is a pain to clean. These skimmers are "relatively" twitchy. You gotta clean the injectors regularly, and you have to keep in mind back pressure etc... when you set 'em up. These skimmers do require a relatively large pressure rated pump to run well, and the purchase price doesn't typically reflect this. There are a lot of options of this type of skimmer and generally they perform similarly controlling for size and pump used.
Needlewheels tend to cost more, but give more "plug and play" capability. Tend to be very, very simple to setup. Much more energy effecient than becketts b/c the pumps are much smaller. Recirculating/external designs are more "effecient" and you pay for it. The kings of the hill are Deltec and H&S, which is what the ER/ASM units are modelled after (and the other units like corallife superskimmers etc...). The Bubble King is a "boutique" skimmer, and is priced like it. They are great performers, but $$$$$$$$. Needlewheels tend to be very quiet and energy effecient. In particular recirculating designs that are fed via the overflows are really good, effecient performers. Large, submerged non recirculating models you need to watch out for b/c the pumps can potentially add a significant amount of heat. Also, there are very subtle differences amongst the players in this catagory that can make significant perfomance differences.
AquaC is the "jack of all trades". They work ok, but don't really excel in any area. They need larger pumps to work than a comparable needlewheel. They don't get the air injection that you see in becketts.
Lifereef falls into the catagory of a "conventional" venturi skimmer. Nothing bad, nothing "special" in terms of performance. Other players in this catagory are Schuran and Grotech. All are "nice" units, but generally for various reasons the other catagories of skimmers are preferred.