Blood Angels - one of the first Warhammer sets I ever got was Death Company, though I don't really like how in recent times the red thirst flaw essentially became 40k vampires...
I always viewed the flaw as more of a metaphoric, insatiable thirst for bloodshed fuelled by revenge, descending into manic rage, not LITERALLY drinking blood...
I don't know whether this has come about and been explicitly defined in any of the novels and is therefore canon but it just doesn't quite sit right with me that they've all now got fangs!
Imperial Fists are a close second - I like their sturdy dependability whilst not being flashy, they just get on with it.