Who is the sleepiest of them all? Write a program or function that takes in a string of the characters -=o. where the -=o's and .'s always alternate, character to character. The string will have an odd length greater than one and always start and end in one of -=o.
Basically, the input will look like a line of emoticon faces that share eyes in various states of sleepiness, e.g.
o.=.=.-.-.o.o

Your goal is to print or return the face that is either the sleepiest or the most awake (it's up to you which you choose). If there are multiple choices for who is sleepiest/most awake then any one of them may be output.
There are nine distinct faces and five levels of sleepiness:
-.- is 100% sleepy
-.= is 75% sleepy
-.o is 50% sleepy
=.- is 75% sleepy
=.= is 50% sleepy
=.o is 25% sleepy
o.- is 50% sleepy
o.= is 25% sleepy
o.o is 0% sleepy

In case it's not clear, the sleepiness percentage is computed by assigning 1 to - for fully asleep, 0.5 to = for half asleep, and 0 to o for awake. Then the sum of the two eye values divided by two is the percentage.
The shortest code in bytes wins.
Test Cases
Sleepiest
-.- GIVES -.-
=.- GIVES =.-
o.o GIVES o.o
o.-.= GIVES -.=
=.-.= GIVES =.- OR -.=
o.-.= GIVES -.=
-.-.= GIVES -.-
o.o.- GIVES o.-
=.=.=.o GIVES =.=
-.=.=.= GIVES -.=
=.o.-.= GIVES -.=
o.-.o.=.= GIVES o.- OR -.o OR =.=
-.o.-.=.= GIVES -.=
o.o.o.o.o GIVES o.o
-.-.-.-.- GIVES -.-
o.=.=.-.-.o.o GIVES -.-
-.=.-.o.o.=.o.-.o.=.-.o.=.o.- GIVES -.= OR =.-
Most Awake
-.- GIVES -.-
=.- GIVES =.-
o.o GIVES o.o
o.-.= GIVES o.-
=.-.= GIVES =.- OR -.=
o.-.= GIVES o.-
-.-.= GIVES -.=
o.o.- GIVES o.o
=.=.=.o GIVES =.o
-.=.=.= GIVES =.=
=.o.-.= GIVES =.o
o.-.o.=.= GIVES o.=
-.o.-.=.= GIVES -.o OR o.- OR =.=
o.o.o.o.o GIVES o.o
-.-.-.-.- GIVES -.-
o.=.=.-.-.o.o GIVES o.o
-.=.-.o.o.=.o.-.o.=.-.o.=.o.- GIVES o.o
Pyth, 12 10 bytes

hoSN%2.:z3


This prints the sleepiest emoticon. Verify all test cases at once  in the Pyth Compiler.

Credit goes to @Sp3000 for the idea to use sorting.

How it works

hoSN%2.:z3
              (implicit) Save the in z.
      .:z3    Compute all substrings of length 3.
    %2        Keep every seconds substring. This discards non-emoticons.
 o            Sort the emoticons by the following key:
  SN            Sort the characters of the emoticon.
                This works since '-' &lt; '=' &lt; 'o'.
h             Retrieve the first, minimal element.