My favorite distribution is Gentoo, for 7 years now.
Here are some of my kernel configurations I use:
- Dreamplug: latest public Grsecurity kernel 4.9 (before, I used precompiled kernels from Xilka);
- Cubieboard 2: Linux 3.4 custom branch for Allwinner A20 (dual-core ARMv7 Cortex-A7 and Mali400 MP2) + upstream patches on 3.4 not merged in the Allwinner tree;
- Odroid-C1: Linux 3.10 custom branch for the Amlogic S805 (quad-core ARMv7 Cortex-A5 and Mali450) + upstream patches on 3.10 not merged in the Hardkernel tree;
- Mirabox: latest public Grsecurity kernel 4.9 for the Marvell Armada 370 (with all available features for the board enabled);
- Cubox-i 4x4: latest mainline kernel, currently 4.12;
- Creator CI20: Linux 3.18 custom branch for the Ingenic JZ4780 SoC + upstream patches on 3.18 not merged in the imgtec tree.