I'm another one who used to read the Xanth novels, I really loved them when I was younger. But recently when I tried to get back in where I left off I wasn't as charmed by the puns and such. Or maybe it was just the newer novels aren't as good? Dunno... You have to be a real fan of puns and silly humor to enjoy the Xanth books. I do highly recommend reading at least the first few in the series though I believe they are worth adding to a fantasy lovers repertoire. My personal favorites were "Ogre Ogre" "Man From Mundania" and "Demons Don't Dream"
But I seriously loved "If I Pay Thee Not In Gold" which was a pairing between Piers Anthony and Mercedes Lackey (One of my all time favorite authors) Very interesting adventure that puts a twist on gender roles.