Given the nature of the Citadel being the tutorial area/place where you pick up Garrus, Wrex and Tali, the rest of the place seems like cake so far.
Shot a couple of thugs in the face getting to Fist was interesting but the conclusion of that story path seemed lacking...
I brought Ashley and Garrus with me because Space Bros and Space Hoes until I can get to Liara later on.
...also, because I knew that if I brought Wrex, while satisfying in the fact that he'd put in a new golf course where Fist's head used to be, I wouldn't get the info I needed to find Tali later on.
Big picture stuff, really.
After I got the info though, Fist learned the true meaning of the holidays as I gave him a new bullet retainer to chew upon.
Fast forward a little more and I've diffused diplomatic tensions between Gen. Not-Garrus, Self-Doubting Elcor and Space Jenna Jameson; got an informant back to her sister while bringing down a tech smuggling ring; and have more gear than I know what to do with.
Still need to find two more Keepers to scan for a guy who may or may not be trying to kill his business partner; stop an A.I. from going Die Hard on Space Nakatomi Tower; get it in with Space Jenna Jameson; and get ready to go and stop Saren from killing everyone...
...should be fun.