Even though this is a pretty much off-topic question rather related to
industrial design, I can give you a hint.
Fonts should be taken very seriously in design, but choosing them should be based on
holistic approach, to be
in agreement with the whole design.
Designers often say that Arial font was poorly designed, so, for a sans serif font (which means the font without "serifs", small strokes at the end of the letters, please see
http://en.wikipedia.org/wiki/Sans-serif[
^]) Arial would be one of the worst choices.
Some highly reputable fonts, just for example, are Calibri (this one is often referred to as the best), Lucida, Corbel, Helvetica, Futura, Avant Garde, Verdana, but not all of them come with Windows or Office. It all heavily depends on some
personal opinions, but there is a number of objective factors affecting readability, so it also heavily
depends on the purpose, first of all. But you can consider also the serif fonts, in some cases even some "accident" fonts.
But please don't take my advice as an instruction for your choice. You really should decide on your whole design. It would be good to take some
design school (possibly online) to develop at least some taste for that. But don't take anything as absolute rules, remember that fonts and all design style are subject to change, a matter of fashion and trends…
—SA