I waffle between a few. Right now, I have a beautiful GEC with jigged bone in front of me, and it just calls to be fondled.
If you look at my collection, you'd definitely see a trend of carbon fiber and titanium. I love titanium for it's versatility, and utility. It takes a variety of finishes, and looks good in all of them, with the exception of a polished finish, as I just can't keep it pretty. Now, give me a handle with both CF and Ti, and I'm probably going to pick it above others. Favorite example, at the moment is the ZT 0600.
I've not gotten into wood. For some reason, I just can't get my mind to accept that it is sturdy enough to keep it's beauty and luster. I do own a few, but it's by far the least well-represented material in my collection.
Okay, maybe G10 is lower down on my list. Not that I have anything against it, but mostly because, if there's both a G10 version and a Carbon Fiber version available, CF will win every time. I think I have maybe 3 G10 knives.