例えば、"At the end of the day, what do you work for?" と日本語で言いたい場合、下記の空白はどんな表現で埋めますか?
"______、何のために働くのでしょうか?"
「結局」だと思うのですが、違いますか。
結局 works, but it's used primarily in the sense of "in the end" to describe what happened last, as in "結局電車に乗れなかった". In your context, you are seeking a decisive and/or fundamental argument rather than random thoughts. In such cases, better and unambiguous options include: