Each company makes something for your need. It's finding the fork that best fits your preferences that is in your comfort zone financially. If you broke the fork on your bike and need a fork and you are low on money, manitou, marzocchi and rockshox make decent entry level forks or you could buy a used fork that is in good shape for cheap. If you want a new fork and you are low on money, save up money for a good fork. If you have alot of money and need/want a new fork, well, the sky is the limit. Just remember to get a fork that will fit your riding style and the type of riding you do. For example, you don't want a Fox 40 RC2 on a Trek Fuel, just like you don't want a Rock Shox Duke on a Kona Stab Supreme. Longer travel forks will put a stress on the headtube of a bike that was designed for xc. RS duke on a stab supreme just looks stupid, and defeats the purpose of a downhill/freeride bike, plus puts a strain on the frame as well. For those of you in between DH/FR and cross country, about any SC fork will do that has 4-7" of travel, some of these SC will either have a 1_1/8" steerer or a 1.5 steerer, sadly for the 1" market the options are dying out quickly. It's just finding a fork that is in your price range. Agressive/heavier riders will be best off with a coil fork, lighter/xc riders will be best off with an air shock. 200lbs riders on air forks have a greater chance to blow a seal. There is though a movement coming around of Air Sprung forks showing up that can take the abuse abuse of lightweight to lighter moderate freeriding and some downhill, but are actually designed for more aggressive trail riding than freeriding. A bike designed around a 3" travel fork can't accept a 5-7" SC or DC, but can accept a 4" fork. A bike designed for a 7-10" DC can handle a 6-7" SC or DC. They can take it, but a coil sprung fork is more ideal for Freeriding and DH, eventually down the line air or nitrogen based shocks* will be the norm.
For those who are craving for a light, fork designed for XC. An air fork is right up your alley. Air forks are starting to show up on 4x rigs as well. Since 2002 the seals on air forks have improved by ten fold. They have no real need for a coil, and the adjustability of these forks are done by air pressure.
Since the first version of the fork buying guide, there has been a movement in the suspension fork industry called the Stable Platform Valve. What is a stable platform valve; it's basically an inertia valve designed to make the fork or rear shock to not respond to pedalling forces(AKA, make it ride like a Rigid) but will reaction to bumps, jumps, rocks, roots. This is big with Manitou, while Fox and Rock Shox have their own variations of it. Marzocchi doesn't but through stratos, you can get a fitting called an ID Cartridge, which is an inertia valve, beware though, this small cartridge is $300USD per cartridge.
Another trend is adjustable travel. All four of the major brands have their own version of travel adjustment, the two that are most known for it however is Rock Shox with their U-turn system and Fox Racing Shox with the Talas system. Manitou and Marzocchi have travel adjustment, it's just that Fox and Rock Shox has it down.
Generally, a short travel fork produces a quicker steering bike, which isn't always a good thing, short forks are great for XC where tracking isn't a big need. A longer travel fork produces a slower steering bike, which osn't good for xc, but for trail riding, freeriding and DH/4X, a long travel fork is a must, a longer travel fork tracks much better than a short travel fork does, tracking is a key element in aggressive situations.
To find a geeral price of this product. Ask your local lbs person or check
http://mtbr.com.
Here are links to various companies that make Suspension Forks.
Companies:
Stratos
Companies that refurbish forks/modify them.
Mojo
Romic
Hippie Tech
Push Industries
*None have been made or have been rumored to being around.
Going to leave this open, but if ANY off topic stuff is posted in this, it will be deleted.