Ask HN: Have you ever taken part in a good 'team building' exercise?

For example, I have been a part of a team that did Briggs Meyer personality testing, which was interesting and encouraged discussion across team members. However, I fear that many exercises or outings would be transparent and a waste of time.

We are a small team of developers who work well together and are a no-BS group. I'm looking to further improve on an already good thing - does anyone have any suggestions of things that have worked for them in the past?