As a forenote: I was not happy with the the skewed romances in ME3, particularly for a traight female Shepard, who really got the short end of the stick.
That said: If you played a straight male Shepard in Mass Effect 3 (without having played the previous games) you got a choice between Ashley (who could be dead) or Liara. If you played a gay male Shepard you got a choice between Kaidan (who could be dead) or Steve. It's not quite as bad as people make it out to be in that regard.
The only thing that really tipped the scales was Diana, and she was such a poorly cobbled together mess that I barely count her as an LI.
That's if you played ME 3 without importing. If you imported, there were actually 6 LIs in ME 3 for straight male Shep (Ashley, Liara, Miranda, Jack, Tali, and Kelly) who all unlocked the Paramour achievement. If you imported, there were only 3 LI's for straight female Sheps (Kaidan, Garrus, and Thane). If you imported, there were 3 lesbian options (Liara, Kelly, and Traynor). Regardless of whether you imported or not, there were 2 gay male options (Kaidan and Steve).
However, if you are just looking at ME 3 without importing, then there were 2 options for straight male Shep (Ashley and Liara), 1 for straight female Shep (Kaidan), 2 for lesbian Shep (Liara and Traynor), and 2 for gay male Shep (Kaidan and Steve).
So that means that:
Straight male Sheps could have between 1 and 6 options (Ashley could be dead; I know people argue that there aren't truly six, because you can only import one, but it doesn't change the fact that there are six female LI's written into ME 3 that a straight male Shep could romance)
Straight female Sheps could have between 0 and 3 options (since Kaidan could be dead)
Lesbian Sheps could have between 2 and 3 options
Gay male Shep could have 1 or 2 options (since Kaidan could be dead)
I guess, to bring it back on topic:
I'm confident that we won't see this kind of disparate distribution between gender/sexuality because: 1.) The DA team is much more inclusive in general; and 2.) We don't have to worry about the import feature.