A natural, common two-word phrase is “me too.” Other good two-word options include:

  • “Same here.”
  • “Exactly right.”
  • “So true.”
  • “Agreed, totally.” (technically 2–3, but often used as a tight two-beat reply)

If you want something a bit more vivid or conversational, “me too” and “same here” work best in everyday speech, texts, and forum replies.