A special note is needed on the naming of anchors. Many anchors have a trademarked name, such as a Bruce or CQR, and a generic name like Claw or Plow. This is the same as how Xerox is a trademarked name for photocopier and how aspirin is a trademarked name for pain killer.
The Lazy Man's Answer (For those who don't want to read this entire article)
For most boaters, a Bruce/CQR/Delta will be the best choice. All three perform similarly and are similarly priced (Narrowly, the Bruce/Claw is our favourite of the three).
If you've used a Danforth in the past, and you have had luck with it, choose a Danforth. If you've never used one before and if your setup allows it, choose a Bruce, CQR, or Delta instead.
If you're a blue-water cruiser, and you have a big wallet, consider one of the new generation of anchors.
Bruce™ Claw Anchor
The Bruce/Claw style anchor was developed in the 70's by the Bruce Anchor Group as an alternative to what was, at the time, the only general puporse anchor available, the CQR/Plow style anchor. Since then, the Bruce Anchor Group has stopped offering anchors to the general public.
The main selling point of the Claw is that it is an excellent all round anchor. It will hold well in most bottoms, although it performs less well in sand and mud. It is also easy to set and to retrieve and has a reputation for not breaking out during wind/tide changes. On the downside, its awkward one piece design can make it difficult to stow. It also has a low holding power to weight ratio, meaning you'll likely require a heavier Claw anchor than you would require for other styles of anchor.
Pros: Performs well in most conditions. Sets easily.
Cons: Awkward one piece design.
CQR™/Plow & Delta™/Wing Anchor
Of the most popular styles of anchors offered today, the CQR/Plow is easily the oldest, dating back to 1933. It competes with the Claw and Fluke styles of anchor as being the most popular anchor amongst recreational boaters.
Like the Claw, Plow anchors are known for performing well in most bottoms, although it does not excel in any one bottom. The hinged shank means the anchor turns with wind/tide changes rather than breaking out.
The most signiciant drawback is the old mantra of boaters "Any Plow under 25 lbs is useless". Because of this, for smaller boats under 30' or so, you'll need a much larger plow than you will for other styles of anchors.
The Delta/Wing anchor is essentially a one-piece plow anchor. It has the advantage of having slightly higher holding strength because of the one piece design but at the same time, it also loses some of its ability to resist breaking out during wind/tide changes.
Pros: Performs well in most conditions. Fits most bow rollers.
Cons: Hinged design can make stowage awkward. "No such thing as a small CQR/Plow anchor".
The Danforth/Fluke anchor is one of the most popular anchors in North America today.
The Fluke anchor performs quite well in mud and sand. When set correctly, the flukes can penetrate the bottom with a lot of force, resulting in excellent holding power. The downside is that outside of mud and sand, the Fluke has very limited holding ability in bottoms such as kelp, rock, coral, etc.. When being set in mud or sand, these anchors do have a reputation for occassionally dragging along the bottom.
For day boaters or to use as a secondary anchor, the Fluke anchor is a suitable choice. For anyone boating overnight where an unset anchor has more dire consequences, another choice of anchor style should be considered.
Pros: Performs well in mud and sand. Arguably the most popular general purpose anchor. Stows easily on most bow rollers.
Cons: Does not perform well outside of mud/sand.
Mushroom/Grapnel and Other Small Craft Anchors
There are a number of anchors on the market today designed for small craft such as
dinghies, canoes, kayaks, and so forth. These anchors are normally small and compact to allow for easy stowage and have no sharp points to avoid puncturing an inflatable. The two most popular styles of these anchors are the Mushroom and Folding grapnel type anchors.
Most of these types of anchors perform well for what they are designed to do. The folding grapnel anchor has the advantage of being extremely compact when folded and it can also have immense holding power when it hooksinto something. That's also one of its biggest flaws: once it is hooked it can be a challenge to retrieve the anchor.
Pros: Great for use as a lunch hook. Folds to allow for compact storage.
Cons: Not appropriate for non-temporary anchorage.
New Generation Anchors
There's been a relative surge of new anchors hitting the market in recent years. Some of the
most common of these anchors are the French Spade, the New Zealand Rocna, and the Bulwagga. These anchors are designed to set quickly and create high holding power. Some of them, such as the Rocna, have a roll bar at the back which is supposed to ensure the anchor does not land on its back when trying to set it.
Many of these anchors have performed extremely well in third party tests. The biggest downside to these anchors is they can be very expensive (up to 10x the cost of other anchors: you're paying for their R&D costs) and they have little reputation, good or bad.
Pros: Very high holding power for many models.
Cons: Very expensive. Unproven.