Strings are very subjective, so I suggest you buy a few different pairs and decide for yourself what works best. That being said, I have tried quite a few and prefer Savarez Alliance fluorocarbons for my mahogany tenor. I don't use the 150R set that they sell for the uke, but instead use singles from the 540R Alliance classicals. I prefer the slightly higher tension and the richer, warmer tone that I get from the slightly larger diameters that I'm using.
The 150R set is made up of the 540R Alliance classical strings by the way, just slightly thinner diameters on two of the strings.