Fights that didn't live up to expectations

I was just rewatching Shields vs Maia and thinking how while it wasn't exactly the most fun, it was exactly what was expected of it. What are some fights that just didn't provide what they should have?

For example, when Mir vs Barnett was announced I was stoked at the idea of seeing a genuinely interesting, quality heavyweight grappling match, and we all know how that went.

Any more for any more?