The simplest answer would be
--Setup a test table called "t1"
create table t1
(date datetime,
value int)
-- Load the data.
-- Note: date format different than in the question
insert into t1
Select '5/18/2010 13:00',40
union all
Select '5/18/2010 14:00',20
union all
Select '5/18/2010 15:00',60
union all
Select '5/18/2010 16:00',30
union all
Select '5/18/2010 17:00',60
union all
Select '5/18/2010 18:00',25
-- find the row with the max qty and min date.
select *
from t1
where value =
(select max(value) from t1)
and date =
(select min(date)
from t1
where value = (select max(value) from t1))
I know you can do the "TOP 1" answer, but usually your solution gets just complicated enough that you can't use that for some reason.