I don't think there is a consensus on which stones are "best" There are different types of stones and each has their own peculiarities. A lot depends on personal tastes as well as what you are sharpening (some work better on carbon steel, some on stainless, some retain just the right amount of water, others are almost non-porous and need splashing or spraying, some are really soft and easy to gouge, others are glass hard and some in between). And, there are just WAY too many stones for anyone to afford to try them all. (if you don't mind trying to figure out the strange Japanglish translations that babelfish comes up with, you can fire it up and find quite a few reviews of synthetic and natural stones here
http://www015.upp.so-net.ne.jp/toishi-erabi/index.html -under the menu selection on the left frame with the "new" tag under it).
for carbon, I like my MinoSharp 1k (a red clay stone. A bit finer and slower than a Shapton 1k but has a nice "feel" leaves a nice matte finish and holds the right amount of water so it will only look damp but water will well out around the edge of the knife when you get the bevel flat on the stone, creates a bit of slurry and doesn't dry out on me). My natural aoto blue stone (very messy, makes a lot of mud, but the feel and sound make it a pleasure to use, and you can work the mud to a decent medium polish). A natural awase (medium hard, holds water fairly decently and is somewhere between 6 and 8k, makes a little slurry and leaves a shiny open finish, but leaves a dark brown haze on stainless)
For stainless, the Shapton pro's may not cut stainless or tool steel as fast as they can carbon steel but they are still pretty fast and they leave a clean bright finish and hardly wear at all compared to most brands (but are very hard so lack a good tactile feel and don't hold water). Bester coarse stones are also good (a bit slower, but fast enough and don't dish as quickly as a lot of others either) and a Naniwa 10k (very soft and wears faster than other ultra-fine stones, but has a decent tactile feel and leaves a nice finish).
The Shapton 2k is one of my favorites for either stainless or carbon... cuts very fast, holds more water and has a bit more "feel" than the finer grits and leaves a much smoother finish than the 1k. It has a good balance between speed, finish and feel, though I wish it held water like a clay stone. The Naniwa 10k is an ultra-soft stone that takes some getting used to but has a nice feel and is great for polishing (more than sharpening) either carbon or stainless. The 10k seems good for hard steel... it wears quickly due to its softness so cuts fast, forms a bit of slurry even without a nagura, has a decent tactile feel for such a fine stone. It does gouge easily so you have to be careful but is less likely to damage or round your edge due to free-hand slop (if you get too sloppy, you'll gouge the stone and have to resort to edge-trailing strokes) The Shapton cream (12k/15k depending on the packaging) is a very hard stone so should be good for controlling the edge on softer steels, but is like sharpening on a hunk of glass (cuts quickly even though it lacks a good tactile feel) and not at all forgiving of slop (can easily round or dull that nice sharp edge you had on your medium polish stone unless you are good at holding a consistant angle... if you are, then it will produce a wickedly sharp edge).
Suehiro 6k is a medium soft stone. Leaves a decent finish but the slurry may grab smooth flat blades (the slurry can make a nice vacuum seal between the stone and the back of a plane or something). It is a tad slower than the Shapton 5k, but also seems to work on carbon or stainless and seems a decent alternative to it when you want a softer stone.
For hogging metal I like the arato kimi PA 220 (pink/white 220 grit aluminum oxide brick from Epicurian Edge or Japan Woodworker)... hogs metal, but doesn't wear as fast as SiC stones seem to and leaves a finish more like a 400 grit.
Stones I haven't used but have heard good things about... King G1 8k, Kitayama 8k (can polish like a 12k), Takenoko 8k (not as smooth but faster cutting). I've also heard good things about the King F1 (4k). Norton waterstones (a bit coarser than the same grit in a Japanese stone but cut fast and are cheaper since they don't have to be imported). Naniwa Snow White 8k (a magnesia stone like the Suehiro's... not the same as the super ceramic series which the green 10k is a part of). Arashiyama... has natural stone powder in it and works like the Kitayama (but I'm told it is better for traditional carbon steels rather than tool or stainless). Shapton M15 and M24 series (also rated highly but are more traditional stones, so form a slurry and some may prefer them to the pro series)
Good places to get them can be found on this thread on knife forums
http://www.knifeforums.com/forums/showtopic.php?tid/759892/
