Within the past couple years, there's been increasing Chinese competition in the mechanical keyboard market. They are competing very well on price but build quality for the most part continues to be subpar in comparison to the competition. The companies who build them have a tendency to be mysterious (also Asian companies don't tend to operate in the same way that Western companies do) and it can be difficult to get information on them. As such, if you have to RMA such a keyboard for a defect you may find it difficult. Listed here are top competitors right now.
CM Storm Quick Fire Rapid
This keyboard is a Filco clone (made by the same company, in Taiwan). Thus far, this keyboard looks to have the best build quality of the Chinese clones. At the moment, these are only available in China.
Photo courtesy of leotnnz
KBC Poker X
The Poker X is an HHKB-sized mini keyboard available with various Cherry MX switches. It is PCB-mounted and is available with both Lasered ABS and PBT keycaps. It has Full N-key rollover over USB and works on Windows, Mac and Linux. You can currently find them available new on ebay.
Photo courtesy of csm725
Noppoo currently makes two keyboards: the Choc Mini (space-saving layout) and the Choc Pro (full-layout). Last I checked, they are both available on ebay in various Cherry MX switch types. They both are plate-mounted and have Lasered POM keycaps and full N-key rollover over USB. The Choc Mini does NOT work on Mac.
The Rapoo V7 keyboard is a tenkeyless Cherry MX clone keyboard. The switches are yellow and have been said to feel similar to Cherry MX Blacks. They are made of ABS plastic and rubber and have lasered ABS keycaps. General availability is not clear at the moment but here is one retailer (They are located in China but will accept USD and ship to the U.S.).
Photo courtesy of reaper
Ducky currently makes several types of keyboards but the most popular are the 1008, 9008, 9000 and 1087. All of these models are currently available on ebay in various Cherry MX switch types. All are plate-mounted and are considered to have fairly decent build-quality in comparison to most of the Chinese competition, with the exception of the 1087 (which has ABS Pad-printed keycaps). The other models are available with PBT engraved keycaps.
PLU currently makes two keyboards: the PLU-87 (tenkeyless with 2-key rollover) and the PLU-G3000 (full-size layout with n-key rollover). Both are plate-mounted and currently available on ebay with various Cherry MX switch types and POM Lasered keycaps.
Photo courtesy of mrsone