The simplest and most effective way to respond to "I love you 3000" is to reciprocate the sentiment. However, you can also add a bit of playfulness and reference the source material.
Here are some options:
- "I love you too."
- "I love you tons!"
- "I love you 3000."
Essentially, mirroring the phrase back is perfectly acceptable. The key is to respond in a way that feels genuine and comfortable for you.