The counterpart to 決定 is 選択 (せんたく); this is what you are locking in when you 決定. 選択 appears non-stop in manuals and games and is basically a way of saying 選ぶ (えらぶ) with a compound noun. “Choose” and “select” are both options, but I think I prefer the latter, possibly because it’s more flexible: it works as a plain verb (“Select an item.”) as well as “noun” (“Mode Select screen”). “Choice” and “selection” can be used when it is a real noun.
I love game lingo, and yea you’re right, ‘select’ is definitely a more rounded and user-friendly translation, though in most dictionaries, it’ll always be listed as ‘choose’ first, annoyingly..
The best thing about 選択 is sometimes finding it slip through in the Japanese source as 洗濯. Hit ○ to do your laundry!
Haha…hooray for 変換ミス.