In order to answer this question properly you really need to give more details. People will need to know what type of riding you do, if weight's an issue, if price is an issue, and how much you weigh may help as well.
I've ridden a few but only have alot of experience with Maguras. Because of the experience I have with them, that's my brand of preference. In fact, I just picked up the new Marta Carbons but haven't been able to install them yet. I may wait until spring anyway, let my old ones run the few times I get out in the winter. They also run on mineral oil.
The big advantage to mineral oil,in addition to the lack of environmental impact, is that it is not hydroscopic (doesn't absorb water) which could cause various issues if too much water is absorbed. I'm familar with the effects of water in relation to autos, but not exactly sure if you could heat bike brakes up to boil the fluid or various other issues that can occur.