Any Abit board from their heyday. Out of the ones I owned, I'd say the AI7 (Pentium 4) and AN8 Ultra (Athlon 64).
I liked the overclocking ability of course, but I especially liked the hardware monitoring and fan control options built into these boards. The AN8 was especially good and allowed you to connect an external hardware monitor and overclock tweak gadget via a custom port on the board. Abit have done the one and only implementation of this feature that I've ever seen, which is a shame. It was so innovative, I think today's manufacturers should do the same.
Oh, sod all that, I just liked the orange motherboard colour!
![Roll :roll: :roll:](https://tpucdn.com/forums/data/assets/smilies/roll-v1.gif)