This answer won't point you directly to a specific recommendation, but I would like to point out to you that there are fonts which are designed for use on computer screens. What makes them different than other fonts is that they lack detailing that would be either lost or non-gracefully degrading when limited by two important factors of the screen:
- low resolution (especially compared to print, such as 72+ dpi versus 600+ dpi)
- small size -- given that apps will typically display type in the range of 10-12 points
The standard-bearer for this was set with the Macintosh which had some fonts intended for the screen and not for print:
- Chicago, a bold font for menus
- Geneva, a sans-serif font for on-screen use
- New York, a serif font for on-screen use
- Monaco, a fixed width font for on-screen use
I seem to recall that even when the proliferation of outline or vector based fonts came about (via True Type, but Postscript with Adobe Type Manager was a common standard prior to that), there was an insistence by some that the on-screen fonts should be just that. Eventually, though, there were outline versions released for those fonts.
The rule of thumb was that city-named fonts were for on-screen use, and the other fonts (Times, Helvetica, etc.) were for print. Fonts for on screen were available to the operating system at various, common point sizes and there was not a standard system of smoothly scaling the type outside of the point sizes contained in the system (again, excepting Adobe Type Manager or "ATM" and PostScript, and later, True Type).
So if we pay homage to history, the takeaways are this:
- Choose something that gracefully scales down in size and resolution
- Ideally, pick a font that was designed for the limitations of video screens
In 2010 Adobe partnered with Typekit to improve some of it's very established typefaces, modifying them for today's on-screen capabilities (improved DPI, antialiasing, and vector based rendering). That partnership has made available over 500 type faces (not quite the same 1:1 as "fonts").
(If you care, see "What's the difference between a font and a typeface?")
Using Typekit, you can very affordably license the use of the standard maker's well accepted fonts. There are over 500 faces in the library (not all are Adobe sourced), containing such well used fonts like Myriad Pro. Personally, I'd steer you toward choosing three types of faces:
- a "Heavy" weight for top-most menus, and alertbox titles (possibly Heavy and Condensed)
- a Sans Serif font for other non-user generated UI text, two weights: bold and medium
- a Serif or Slab Serif font, one that might even been meant to complement your choice of Sans Serif fonts (sometimes similarly named, sometimes it's just suggested as a complement) -- this, I'd use for larger passages of text and or the text that is entered by the end user
Here is a link to the Adobe fonts on Typekit, you can't go wrong with using this as your selection pool:
http://typekit.com/foundries/adobe/fonts/
Personally, I like:
- News Gothic Std, bold
- Myriad Pro Semi Condensed, light or regular
- Minion Pro, regular
(respective of the order of the categories I mentioned earlier)