Kind of interesting seeing someone with a custom UI using the default fonts... doesn't seem to be done very often. :P
I'm using Fritz Quadrata...is that the default? lol *shrugs*
I use what's clear and easy to read. My preference is Skurri, but I couldn't get, for the life of me, any fonts to "take" on the tooltip mod, and I hate having multiple fonts...it detracts from the overall look, to me.