Ryzaki wrote...
I think it's less Shep can't and more he/she doesn't bother learning. (Either that or that heavy ass armor gets in the way).
I think this is more the case with Shepards who are Sentinels or Adepts, not that they couldn't learn to do it they just didn't. Vanguards kind of do something similar with Charge, but of course that just slingshotting themselves from point A to point B. At extreme high velocities and with the intention of doing serious damage to the person they are launching themselves at. So a Vanguard Shepard could charge herself down to the second level, but would be leaving her companions behind. Hence Shepard's dialog about her and Kaidan both being out of luck on that one.
(also when does Jack float?)
Grissom Academy. She jumps out of that window, after you defeat the Cerberus troops in Orion Hall. I wouldn't say she floats exactly, but she does soften her landing with her biotics.
As to the actual topic at hand, I take Garrus everywhere in all three Mass Effect games, (as he's usually who I'm romancing) so it all depends on who works well with Garrus.

So this is who I take and why.
ME1:
Therum: This is one of the few places that I like to take both Kaidan and Ashley. "Dare you to spit over the side?"
Feros: Garrus and Tali. I like the insight that Tali brings to the mission about the Geth and I like that look Shep and Garrus exchange just before going down to deal with the Thorian.
Virmire: I actually like take either Liara, Kaidan or Ashley when you find the beacon there just because they are the only people that would recognize it as like the one on Eden Prime.
Noveria: Liara for obvious reasons. And usually Garrus, but Wrex and Ashley have unique dialog here when deciding what to do with the Rachni queen.
There is one side mission in ME1 that I always take Kaidan on and that is the one where those biotics are holding Chairman Burns hostage, since he has unique dialog there.
ME2:
Mordin Recruitment: Garrus and Zaeed. Garrus for drama and for some unique dialog from Mordin about Turians and humans.
Jack Recruitment: Miranda. I like to think it's Miranda's comment about knocking Jack out that sparks their animosity. I know Garrus will say the same thing if you take him with someone else, but it doesn't have with same "bite" that Miranda saying it does.
Grunt Recruitment: Jack (with Garrus again) mainly because she's one of the few characters that doesn't complain when Shep makes that merc think he's going to bleed to death.
Horizon: I like to take Jack and Garrus. I like what Garrus says to the VS (and it's interesting to point out that Garrus calls Kaidan by his first name and Ashley by her last name) and Jack's line "Whatever you say, Boss Lady."
Collector Ship: Garrus and Miranda. I like to think this is where the cracks start to form in Miranda's perception of the Illusive Man and Cerberus.
Derelict Reaper: I like taking Garrus and Jack. Just because Jack has Shockwave and so does my Vanguard Shep. Blitzed husks everywhere!
Collector Base: Miranda. For reasons.

ME3:
I like taking Garrus with Liara on Eden Prime. Just because I think the three of them (Garrus, Liara and Shep) represent this cycle well to Javik, "Human, asari, turian."
And Garrus and Liara on Sur'kesh as well because of their banter.
Garrus or EDI on Grissom Academy. Just because if you played Overlord and sent David Archer there then he recognizes either of them. I also like to take James.
Kadian on both Lessus and Gellix. For the aforementioned dialog and for that conversation that you have post mission, respectively.
Garrus is good for both the downed turian ship and the Citadel Coup just because he's a turian and he's exC-Sec. Makes for unique dialog.
I also like to take Garrus on the Geth dreadnaught with Tali because of their banter.
I know I take Garrus too many places.