I'm not sure if Bioware has ever come out and said they were inspired by our real history when creating this world or not, but when I was playing the ME games I couldn't help but equate some of these aliens or conflicts with certain real world ones.
Quarians = Muslims/Arabs - They're covered head to toe, both take pilgrimages, to outsiders their customs are strange/weird, both lost their homeland, and so on.
Krogan history = Europeans colonizing Africa - Krogans were tribal and the other supposedly more advanced aliens used them for their own needs, which could be paralleled to Europeans stealing the natural resources of Africa and kidnapping millions of the people for slavery. In both cases, once they stopped being "useful", their growth was purposely stunted.
Turians vs. Humans = UK vs. US - The old top dog fighting the new one.
There are a few more, but I was mainly curious what parallels other people drew when they were playing.