It's gotta be comic sans for me, so fun and delightful, equally great for a children's birthday party or a ground-breaking scientific paper.
The best is Univers, it's just a timeless font.. Thanks A. Frutiger!
Futura at the moment but that'll change soon enough i'm sure...
Currently Circular from Lineto Foundry.
There's something absolutely alluring about helvetica in bold. For now that is, always changes.
i use ashbury from hoftype for my correspondences i kinda like the classic serif feel of it
RBNo3.1 as of now. No idea why but that's my first choice.
DIN an enduring classic
Neutra Text and FF Mr. K Pro Regular are both amazing.
Maison Neue form Milieu Grotesque