ME1. It was a little spicy without being trashy, and it felt like a romantic, intimate moment between two characters who knew each other and knew they might be about to die.
ME2's "love scenes", if you could call them that, were just tame unless they were slightly trashy (Miranda/Jacob) and only the Thane and Jack ones had elements of actual romance.
I felt involved in ME1's love scenes, but not much in ME2's. Too bad, because I found Thane more appealing than Kaidan. (And Feron more appealing than anybody except for Joker, though probably I won't get the former. The latter I'm still hopeful about.)
Plus, I wanted to see a shirtless drell. Imagine my sad little face when he kept every single scrap of clothing on. So unfair. How am I supposed to not think of him as being somebody's dad and former husband when he never takes his shirt off? Dude, this is a guy with a
perfect memory. I've already been informed that he will never forget what it was like to have sex with his perfect wife, can't I at least see his chiseled green chest to salve the emotional pain?

But I'm optimistic that ME3 will be less conservative/short/shirted in terms of romance.