What Excel skills are most valuable for finance and accounting?

Answer 1

My recommendation would be to start with a basic understanding of Excel.  This will make it easier to understand the more advanced features which include vlookup, pivot table, etc.  A basic working Trial Balance will use =sum, =average.  In addition, for financial analysis you will use =sumif, =pmt, =ipmt, =countif - to name a few.  

Answer 2

Knowing all the financial functions as well as most famous excel functions such as vlookup, pivot table, hlookup, sumifs, etc etc