There’s been some discussion lately on ditching the phrase “Delaware Valley” in favor of some variant of “Greater Philadelphia”. The reason given is that “Delaware Valley” allows (suburban) Philadelphians to dissociate themselves from Philadelphia.
I admire where the sentiment is coming from, but for now, I can’t see the language choice as important enough to police my own language or scold anyone else for theirs. This may change in the future, or it may not. Still, I thought I should make a note for those as do care.
Sic Transit Philadelphia 
“Delaware Valley” fans are happy with a name which excludes not only Philadelphia but also Camden. (After all, the Delaware has two sides, last I checked!)
When speaking to non-locals, I describe where I used to live (Swarthmore, Bryn Mawr, 46th & Springfield, Lansdowne) as “various places in and just outside Philadelphia”, and when speaking of specific those three “Delaware Valley” towns I tend to call them “towns just outside of Philadelphia on the commuter rail” (which gives folks a clear sense that they are rather close by and absolutely part of Philadelphia’s economic sphere); “Delaware Valley” is meaningless to anyone who isn’t local, and “Philadelphia suburbs” just doesn’t feel right for a place like Swarthmore somehow (too much transit to be a suburb?).
The “Pioneer Valley” — a term coined by the business/tourism industry — has very specific road-sign demarcated borders on its north and south ends which cleverly exclude the impoverished towns to the south for no adequately explained geographic or topological reason.
Swarthmore is 100% a suburb. It’s a primarily-residential community near a city. It doesn’t fit the standard late-20th century, car-dependent model of “suburbia”, but neither do Bryn Mawr or Lansdowne.