I get the same result as you when testing your data, must have something to
do with the highest value being in the left most column as if you make B the
higest value it gives the correct result. Has me stumped as well. May have
something to do in the sorting of the numerical data.

"J" wrote:

A1 - "A"
B1 - "B"
C1 - "C"
A2 - 3
B2 - 2
C2 - 1

D2= is returning the MAX in the A2:C2 array and returning 3

E2 is my LOOKUP function. =LOOKUP(D2,A2:C2,A1:C1)
Which I thought was saying, look in the array a2:c2, find the value in
d2(3), and return the corresponding value in the a1:c1 array, which would be
"A".
I would be expecting it to return a value of "A" but it's returning "C"
instead.

I've tried VLOOKUP and HLOOKUP and haven't be able to get that to work with
this either. Any ideas what I'm doing wrong?