Dwarf Ironbreakers.
a 4+ save.... really? these dudes are supposed to be the armouriest dude around more or less. Yeah they got a a special rule but I can't think of why they shouldn't be 3+.
because they have 2 special rules that make them annoying, one to reroll all failed save rolls and one to ignore rend (well a bit) but still, pretty tough... they are also good at melee and have range attacks and cause d3 mortal wounds at range if they wish, they are highly versatile and tough as nails