There are countless corkscrews available that cost less than $20, but they don't all perform the same. According to reviewers, some are definitely better than others.
Excluding lever types like the Metrokane Rabbit models, the waiter-style Pulltap Corkscrew 5100 (Est. $7) earns the most consistently high ratings from professional reviewers and owners. While many waiter-style openers have just one hinge, the Pulltap has two, turning cork extraction into a two-step process. First you engage the brace against the bottle using the first hinge and pull the cork out halfway, then engage the brace using the second hinge and pull the cork all the way out. Reviewers universally like the design, saying it makes extraction much less strenuous. About.com's Stacy Slinkard names the Pulltap one of her favorite corkscrews, saying the double-lever lift system "helps win the battle of the cork." She also calls it durable and likes that the screw has a full five turns.
As for owner reviews, nearly 60 Amazon.com users give the Pulltap Corkscrew an average rating of 3.1 stars out 5. Comments include "works perfectly," and "nearly perfect in its engineering and functionality," and many call the wine opener easy, compact and efficient. The foldout foil cutter also draws compliments, with one owner saying it makes a "nice, clean cut." Of note, several reviews come from those whose jobs require them to open multiple bottles a day.
Most of the complaints about the Pulltap come from users who find this model to be of cheaper quality and construction than more expensive Pulltap products. Several thought they were buying a better version, and feel cheated or fooled. Pricier Pulltap models are available at many websites and cost between $10 and $35.
For those who like the idea of a basic, inexpensive corkscrew but want something a little dressier than the Pulltap 5100, the True Fabrications Wood Professional Corkscrew ($12) gets excellent reviews. Like the Pulltap model, it has a double-hinged design, a five-turn screw and a foil cutter, but it has a wood handle and costs about $5 more. About 100 users post comments at Amazon.com, giving the wine opener 4.8 stars out of 5; reviewers include servers who open multiple bottles a day. They say the True Fabrications is well made and effortless, and call its wood handle rustic and classy. A few find it hard to use, however, and one complains that the foil cutter is awkward for left-handed people.