The one used in most mining farms during 2013 was Bitfury/BioInfoBank 55nm chips they run at 25GH for 25W per blade (16 chips) but can run faster if you put more power to them and add cooling BitBurner Fury got them up to 52GH.
http://www.bitfury.org/ and http://www.bitfurystrikesback.com/ and https://megabigpower.com/ and https://www.asic-hardware.com/

They just sold a $5million contract to some investors. http://www.businesswire.com/news/home/20140123006299/en/CoinSeed-Invests-5-Million-BitFury-Bitcoin-Mining#.UuQrHPvLe00 in 2014

But that was not the first one also see the BioInfoBank 100TH Mining Farm Project https://picostocks.com/businessplan/19.pdf is from 2013.

If you have any sense you will write your dissertation about whether the BioInfoBank 100TH mining project reached it's investment goals as it's set out in a clearly defined business plan that you can critique it with hindsight.

Hashfast and KnC have delivered more efficient 28nm products, but KnC limits production runs, and Hastfast is too new to know reliability (arrived this week).