I tend to be more drawn to the older stuff, but the E90 (particularly the E92) M3 still looks great to me
The E46 M3 was always let down by its too-small front wheels and 4x4 ride height. Once lowered a bit, with some wider wheels and tires, it starts to look mean. Still crosseyed, though
I love the look of the E36 but it looks so dated today. I think a big part of that is the headlights.