Of course there can be more than one best. You just have to use different criteria - for example, max personal dps vs. max raid dps. Or shortest mean time to get. Or anything else in general - including “best looking”.
If we’re to minmax though, then we would be talking about highest increase to team (raid) performance. And I highly doubt there a universal answer to this - for all possible raid sizes, compositions and encounters. There isn’t unless it’s mathematically proven. I haven’t seen a proof; so unless someone provides a link to a solid, logical and mathematical proof there is a “best for all cases” type of gear, even just for one slot and one class - it’s safe to assume there is none.