Low's Peak, Kota Kinabalu, Sabah, Malaysian Borneo.
Severely dehydrated, severely under-dressed, severely cold (the sum of these parts means, of course, that I am severely stupid) my travel partner and I dragged our sorry carcasses through the woods and over rocks in the dead of night in search of Low's Peak. We found the peak, and under cover of dark we sat huddled together in an effort to get warm. And then the sun peaked over the horizon, and everything changed. I was still damn near freezing to death, but at least I had a smile on my face.
Kota Kinabalu, for all it's commercialization, is still a brilliant climb. This is the 20th tallest mountain in the world by virtue of topographic prominence, and you'll feel every inch on your way to the top.
Do it - expensive by SE Asian and Malaysian standards for activities to do, but 100% worth it. Two day hike with an overnight in the mountain lodge, it's more than just reaching the peak, it's a whole experience which is second to no other that I've experienced.