Depending on the guy, but some guys just think its really sweet if you call them babe or sweetie or hun or anything like that. And if you do make up a really silly nickname for him, he will just know how comfortable you really are with him.
You can be generic: baby, babe, boo, sweetie, hun, love.
Or just call him sexy and/or handsome.
But you're better off thinking of something unique, and only you can think of that.
Relate it to him.
My ex was addicted to blueberries, so I called him booberry.
An abrieviation of his name, or something having to do with his personality.
hunny bunny, baby boo, miester, the bomb, rocket scientist
if it is a boy then they are flirting. if it is a friend then it is a nickname
depends on the nickname.. could be good or bad
T or Tychick
If you're a boy, STOMPZ
there is many complements you could give a boy such as your awesome , your a great friend ( if he is your friend ) , your a encredable person and ,if he is a wacko you write your really out there ;)
If you are really good friends only (with a female) then 'buddy' is just fine. Often men of all ages will refer to a good friend as a 'buddy'.
This really depends on what your boy friend likes. Get him what HE likes.
K-boy
charlie
max, axe
andrew
psy, Psycho, Cat. Whatever you feel. These are the names that I usually give an espeon. Second answer: A good name would be Psych :3