I like the minimalistic tree style reticles. The March FML TR-1 and the Minox MR4 are both great. The March is much better for lower powers since the center can be illuminated.
[Linked Image from marchscopes.com]
[img]https://images.eurooptic.com/images/products/minox/reticles/minox-mr4-reticle.jpg?w=1100[/img]