The Ten Most Asked SQL Server Related Programming Questions In Newsgroups

I have been participating in newsgroups/forums for about five years now and lately I have noticed that at least 60% of the questions are the same ten questions.
That is why I will create a blogpost that lists these ten questions and also provides an answer for them. I think that to write this will take me about a week.

Here is what I have so far

1 selecting only current day/yesterday from a table
2 adding days/weeks/years/months to dates
3 splitting string values
4 select * from one table that doesn't exist in another table
5 getting all rows from one table and only the latest from the child table
6 getting all characters until some character (charindex + left)
7 NULL stuff ( a bunch of stuff here dealing with nulls)
8 Row values to column (PIVOT)
9 Show 0001 as 1 and show 1 as 0001
10 CASE and checking for NULLs

I guess I could have added date display formatting. Did I miss any other obvious questions?