I just wrote out my character and NPC interations, that is until, I forgot to see how I was going to put in NPC dialogues. I was thinking one of two ways: TextBox - Plain old text-box with some topics which will give a pre-made response In-Screen - The character selects topics from a list and can speak to the NPC directly without any boxes. Which would be easier to implement and be better for the player?

If I understand you correctly, won't a decision between those two types of dialog completely change the game itself?

I don't think it's nearly as important to make it better for the player as it is to make it better for the game. Choose the one that fits your game the best. If your game is fast paced and exciting, then stick with simple decision making. If it's methodical, give the player a lot of control over what to talk about.

Games like Fallout and Star Control II are methodical. Games like GTA are fast paced. Deus Ex is somewhere in-between. That's not to say that either system won't work for either scenario. But few people take joy in smashing through hordes of enemies with crowbars and chains, then stopping for an hour chat with the crime boss. It's usually "[Yeah?].. [Oh yeah?] .. [Die!]".

Well, I just cannot decide. The game is supposed to be somewhat fast paced similar to Baulders Gate, while having gaming elements from the Elder Scrolls series.

I think that using a combonation like you said was a good idea, I will start the implementation of a combo right now. Thank you.

<Edit>

I forgot to mention that I made it so that the interactions are not binded to the dialogue style.