I'm having a blast with Fallout 4, it's actually quite awesome so far, but I've got to say... this dialog system is easily the worst thing that's ever happened to the series, at least in my opinion. I've never played Mass Effect, so I don't know how it compares to those games, but this just sucks so much of the fun out of it for me. The other two fallout games were fine because while there wasn't always an option that had what you wanted to say, you at least knew which one would be closest, and if you didn't want to say any of them, you could probably back out. This time, it's a crapshoot where you have to just pray that the option you choose is the one that's going to say what you want.
For example, I'm on my way to Diamond City, and I get a distress call on my radio from a bunch of Brotherhood of Steel guys who are holed up nearby and need some help. So I go over and help them out with some ghouls who were attacking their little base, and after they're done the Paladin guy asks me what my business is there. I have several choices, but the one I'm looking for is the one where I'm saying "I came because I heard your obnoxious little distress signal". The closest one I saw to that was an option labelled "My Business", which seemed vague, but I thought for some reason that I would actually be telling him why I'm there. Instead I say something standoffish like "That's my business, not yours", and then he gets all huffy with me about it.
Turns out the only other option I had was that I'm "just trying to survive", which is absolutely untrue, both in the short term and long term. I'm not just aimlessly scavenging, I'm trying to find my kid, this is supposed to be the big motivation for my character. And don't get me started on that landmine of a "Sarcastic" option, I never touch it. You have no idea if you're going to be saying something that's just a bit of harmless dry humor, or you're going to say something that cuts right to the bone of the person you're talking to.