I’m not a typographer. These are (mostly) the Microsoft C* fonts that are freely available across platforms and included with Office (and Windows eventually) since 2003.
I’ve been using Cambria for a while as my main body text. Distinctive yet I can count on most everyone having it. Calibri is where I go for sans-serif - especially when sharing the page with Cambria. I think their x-heights are similar and so they pair well. Calibri is the default font for most Office apps now (unless you go with a template).
I don’t use Constantia or Corbel much - but I’ve grouped them here because, like Cambria and Calibri, I think their similar x-heights pair well. If I go with one, then I’ll also use the other. Lots of respect for both on the web.
Candara seems to garner a lot of praise. I wonder, however, if that’s just because it’s not really used much. Interesting swells along the letterforms, but it starts to feel like Papyrus to me. I dunno.
Franklin Gothic (medium here) seems interesting because, compared to the others, it’s perpetually bold. I might start using that in email replies if I embed my response inline with the original message to help make it stand out. Of course, it’s not a C* font. Just mentioning it.
Consolas is great for showing code or any other situation where I want a fixed-width font that needs to be shared with others. For personal use, I prefer the excellent DejaVu Sans Mono… but Consolas ain’t no slouch. Both give me a zero indicator (slash for Consolas, dot for Deja) which I love, love, love. Courier New is old and tired (and not a C* font either). Meh.