Shipping Goggles: Nearly all readers agree that Spain and Lovi are intended to be a couple, notably because the pairing is popular in Hetalia; however, the author has explicitly stated there's no (intended) romance in their alliance.
Vash. After growing up on the streets and orphanages of a place as harsh as District 2, then letting himself be trained as what amounts to a child soldier just to get food and shelter, there's nothing the kid needs more than a hug. Yet he's basically the series' Emotionless Guy.
Igris and Lude (the latter only in the 4th What If) try to be this, but both end up as Not So Stoic.
EVERYONE. IN. THESE. GAMES. Even Wiremu kind of counts, since nobody likes him and thinks he's a disgusting creep. Special points to the victors, since they're still traumatized.
Raivis Lithu is already a whimpering little puppy that "wouldn't hurt a fly", and he earns his woobieness by remaining this way, even while getting his finger chopped off and being killed slowly by poison from a muttated vine.