What apparel worked best for you on ultra-distance events and what didn't?

I see we are asking a lot of questions

Well this one is going to be vague because it depends so much as to where and when the event is.

In South Florida during the summer nearly anything works as long as it can reduce the heat/remove the persperation and so on.

I'm in Berlin now where it is sub-freezing and I find that it takes a lot. My current outfit includes the following:

* Performance Natahala jacket (just bought this and it is WONDERFUL around freezing temps.
* Performance Triflex tights. These have wind blocking front panels and I love them. I've used them in temps down to 20F
* Performance booties heavy. These work well but the zippers tend to slip during the ride. Solution... Use a reflective ankle velcro strap and put it just under the zipper after you zip the booties up.
* Ear muffs. The ones for skiing. They are good for down to freezing but not much more. For extended cold I use a balaclave and possibly the muffs too.
* Pearl Izumi heavy bicycle gloves. These are nice and comfortable. I wear glove liners on really cold days and possibly even a thin pair of gloves too.
* I usually wear a heavy full sleeve jersey under the jacket (use to wear two until I got the Natahala jacket!) and something like UnderArmor t-shirt (tight fit) under that.

Now for something completely different. to keep toasty warm I place chemical hand warmers into my gloves and I wear double socks and place a warmer between the socks. These warmers run for around 5 hours or more and are perfect to keep warm. I carry a few extra in the jersey pocket for a quick change at a control.