what's best in your opinion in terms of cherry switches?
Oh my, that's quite a question
However I better give you some links so you can do some reading on the subject I guess.
However, before I do, a brief run-down on the most common Cherry switches is as follows.
Blue - tactile and clicky (this means there is a noticeable tactile bump before the key actuates, also they make quite a noticeable clicky noise) - These are considered some of the favourites among those who type a lot.
Brown - Tactile but none clicky (so like the blues but without the clickyness, however I am not certain off the top of my head weather the activation force is the same or not) - Good all-rounder.
Black - Linear switches with fairly high activation force (so these do not have a tactile bump or a click action, they are purely linear in action and in this case they are have a reasonbly high activation force requirement) - Good for fairly high intensity gaming, especially FPS games, although some people prefer a lighter switch for intensive gamin sessions, it's really a case of try them and see what you think.
Red - Linear and very low activation force (These are essentially the same as the blacks except they are much more sensitive, in other words the force required to actuate the keys is much lower, more like a brown switch but without the tactile bump) - A bit of a love it or hate it switch, if you like blacks but find them to heavy then this is your answer.
So which is best, well that's entirely personal preference, however 'most' people tend to recommend linear switches for gaming purposes and tactile for typing ...the click is purely personal preference. Many people consider brown switches to be the best compromise all around for gaming and typing. Personally I use a board with red switches ...which are the least common of the above and in my opinion a bit more of a love hate switch than say a brown or a blue. Many people find reds to be too light and sensitive.
And now those links I promised;
http://geekhack.org/showwiki.php?title=Cherry+switches+and+boards
This will tell you pretty much all you need to know about Cherry MX keyboard switches, and probably plenty you didn't even think to ask about.
Geekhack is an excellent source of info with regards to all things mechanical keyboard related. There is also a good European based forum,
http://deskthority.net/ ...lots of members of geekhack there but it's more European oriented.
Oh one thing I forgot to mention, bear in mind that not every keyboard is available with all the key switches. Typically the gaming oriented boards only have one or two options.