There are a lot of characters in Mass Effect and thus a LOT of cosplay examples to share. So what I'm going to do is dedicate a post for each character and show some of my favorite examples that I've found.
We'll begin with my personal favorite, Jane Shepard, otherwise known as FemShep in the community, or whatever you want to name her. She's the female version of the protagonist of the game so of course you can change her appearance how you see fit. This works out great for people wanting to dress as her because there is no one way Shepard is supposed to look. Makes for a lot of variety out there. Enjoy!
http://viverra1.deviantart.com/ Be sure to visit and leave some comments, she did an amazing job on the costume, really spot on!
clefairy-tale.tumblr.com/ Be sure to stop by and add some notes!
https://twitter.com/montirovka_man and check out more of her amazing cosplay work on her Deviant Art page here: http://love-squad.deviantart.com
http://crystalcosfx.deviantart.com She also has a website here: http://preciouscosplay.cleanfolio.com/