Grayswandir
Just a lurker
I think the gods from the PHB are perfectly fine for a campaign, and in fact they get used with little to no changes in most of the campaigns my group runs. Except for me, of course.
In the mini-campaign I run, I use seven homebrew gods: Corruption, Rulership, Healing, War, Sun, Moon, and Nature. That pantheon has, in play, proven to be a bit too small for D&D.
In my main campaign I use a number of different pantheons. The races each have their pantheons, which have been detailed in various products previously. Apart from the racial deities, the only god from the PHB whom I use is Hextor, but I plan soon to reveal that Hextor is the same god as Deimos and thus link him into the Greek pantheon. Once he's firmly established as an Olympian, I can just call him Deimos all the time and pretend I never used a god from Greyhawk. Apart from the Greek pantheon, the Norse and Celtic pantheons are also known (though small), and the Babylonian-Sumerian pantheon(s) was wiped out about a thousand years ago (or was it?). Then there's a few homebrew gods on top of all that - Solarus (think Pelor), Midnight (goddess of psionics), Hmemtyet (god of madness), and Sorecal (TN god of magic), and Serra (don't ask).
Yes, that is too many gods. But most of them are backgrounded. The major gods are: Solarus, Midnight, Hextor / Deimos (currently the greatest god on my world), Serra, Eris, Apollo, Artemis, Hecate, Sehanine Moonbow, and Hmemtyet. I think those nine are pretty much it.
The moral? As far as I can tell, the ideal number of deities is about a dozen.
In the mini-campaign I run, I use seven homebrew gods: Corruption, Rulership, Healing, War, Sun, Moon, and Nature. That pantheon has, in play, proven to be a bit too small for D&D.
In my main campaign I use a number of different pantheons. The races each have their pantheons, which have been detailed in various products previously. Apart from the racial deities, the only god from the PHB whom I use is Hextor, but I plan soon to reveal that Hextor is the same god as Deimos and thus link him into the Greek pantheon. Once he's firmly established as an Olympian, I can just call him Deimos all the time and pretend I never used a god from Greyhawk. Apart from the Greek pantheon, the Norse and Celtic pantheons are also known (though small), and the Babylonian-Sumerian pantheon(s) was wiped out about a thousand years ago (or was it?). Then there's a few homebrew gods on top of all that - Solarus (think Pelor), Midnight (goddess of psionics), Hmemtyet (god of madness), and Sorecal (TN god of magic), and Serra (don't ask).
Yes, that is too many gods. But most of them are backgrounded. The major gods are: Solarus, Midnight, Hextor / Deimos (currently the greatest god on my world), Serra, Eris, Apollo, Artemis, Hecate, Sehanine Moonbow, and Hmemtyet. I think those nine are pretty much it.
The moral? As far as I can tell, the ideal number of deities is about a dozen.