Snafu the Great
Come on, who doesn't like a buxom woman in leather who can hold her own in a brawl?
Here's a combination of official and fan-based art.
http://fc01.deviantart.com/fs20/f/2007/229/2/f/Ninja_Gaiden_Sigma___Rachel_by_sushisyndrome.jpg
http://fc01.deviantart.com/fs13/f/2007/025/6/c/Rachel_ninja_gaiden_color_by_elcheko.jpg
http://www.cs.nott.ac.uk/~dgf/fanart/04/img/rachel-big.jpg
http://pds.exblog.jp/pds/1/200404/16/19/a0014319_222521.jpg
http://faqsmedia.ign.com/faqs/image/article/765/765842/rachel_ninja_gaiden_460.jpg
http://pds.exblog.jp/pds/1/200404/15/19/a0014319_212242.jpg
Here's a combination of official and fan-based art.
http://fc01.deviantart.com/fs20/f/2007/229/2/f/Ninja_Gaiden_Sigma___Rachel_by_sushisyndrome.jpg
http://fc01.deviantart.com/fs13/f/2007/025/6/c/Rachel_ninja_gaiden_color_by_elcheko.jpg
http://www.cs.nott.ac.uk/~dgf/fanart/04/img/rachel-big.jpg
http://pds.exblog.jp/pds/1/200404/16/19/a0014319_222521.jpg
http://faqsmedia.ign.com/faqs/image/article/765/765842/rachel_ninja_gaiden_460.jpg
http://pds.exblog.jp/pds/1/200404/15/19/a0014319_212242.jpg