Bakke's not so bad. The important part was 9-0, that the way UC-Davis implemented affirmative action was unconstitutional, the plurality and dissents mainly disagree with how powell got there, not the result. Officially I think the tally in Bakke was 9-2-1-1-1-1-4 (I think, I don't remember if bluebook has a convention but most court rules are not bluebook and quiet anyways, so even though I think the splits are important in a cite, I leave them out unless split is super-relevant)

US v Booker regards sentencing guidelines and I think is much worse than Bakke since it has 2 majority opinions (Ginsburg joined both) and 4 dissents with a 4 part dissent, 3 part dissent and two single dissents: 5-5-3-1-1-4. Both add up to 19 votes total, but thankfully I've never had to rely on either case in a brief, if I did I'm not sure how I'd alert the court exactly what part I agree with and think is binding.

Some people think 5-4 decisions are weak, and I don't disagree, but I'd rather have a 5-4 with clear distinctions than Booker where its almost incomprehensible to follow who thinks what.

Some of the older cases (e.g., Dred Scot) there are concurring opinions that have no real reason to be there at all, they agree, but don't highlight what's important or give you new information, they just agree, which is pointless. Scot was 7-2 with 6 concurrences and 2 dissents. Only adds to 15 but that full case is 400+ pages long.

What does court do if none of the Justices agree?

It would have no precedential value, the lower court decision would stay in place. See Rapano v US for a plurality decision, but no true holding. This New Yorker article does a good job with explaining the 4-4 tie that was the possibility after Scalia passed away and the Senate refused to have a vote on Obama's nominee. I vaguely remember one or two important cases from law school that were like Rapanos and were 4-4-1 cases with no precedent, but still important decisions that made the casebook because of the discussions on the law, even though they had no holdings, but I can't remember what they were. Those might be persuasive because the SCOTUS is saying what the law should be, but without 5 votes it isn't binding on any court- almost like a law review article at that point.

This isn't what you asked about, but Brumfield v Cain a recent death penalty case was weird because Thomas in his dissent went off on a tangent about the football player warrick dunn, and its weird because it doesn't have much to do with the case and Alito felt he had to write a separate dissent to clarify warrick dunn had nothing to do with anything:

Justice Alito, with whom The Chief Justice joins, dissenting.

I join all but Part I–C of Justice Thomas’ dissent. The story recounted in that Part is inspiring and will serve a very beneficial purpose if widely read, but I do not want to suggest that it is essential to the legal analysis in this case.

So oddball dissenting or concurring opinions happen too.