or maybe someone who is not restricted by written ('too' linear) dialog and develops a personality based on your decisions well, all companions need this... but, What do you people think the next romances should be?
Are you fine with BioWares choice of characters so far?
I'd definitely like this, and I hope the romances will go into this direction at some point. They don't need to do it with all of course, but a few would be really cool to see.
As for the choices, I like Kaidan, though I haven't played the romance out with FemShep in ME3 so far, but it looks sweet. James would've been a logical choice since FemShep can end up with literally no straight romance if you're not into aliens or if Kaidan dies on Virmire or the Citadel Coup.
James was apparently planned as some sort of fling it seems, something that hinted there was more to the flirting, but he never went any further. I would've really liked to have seen this, some sort of "tender" bonding where the character ultimately can't commit in the end (Citadel DLC plays with that in James's case, but FemShep is quite pushy and creepy... her flirting lines are horrible). Would've been bittersweet, but I guess this is not everyone's cup of tea, too.
So, in conclusion, a little more balanced romances between female and male protagonist. If they are "better" is always a matter of taste though 
And I really wish for better flirting lines for the protagonist.