The Disney hotels are not as spectacular as the deluxe resorts at WDW, but they are still nice. The Grand Californian is lovely and so convenient; it's much closer to DL and DCA than the Grand Floridian is to Magic Kingdom! The Disneyland Hotel is much older, but it's still perfectly nice and festive. Some prefer it over the GCH because the rooms are a little larger, and because it has more Disney touches. Kids might prefer the DLH pool over the GCH pool The DLH is a comfortable 10 minute stroll down DTD to the entrance of DCA or DL. Alternatively, you can hop on the monorail into Tomorrowland. The monorail is within about 5 minutes from most rooms (not accounting for any lines at security). While the DLH is not "within" either of the parks, it is still considered at on-site hotel, as is PP. PP is slightly further from the parks, and lacks the nice grounds that the DLH has. It was not originally a Disney property, and doesn't have as much of the Disney feeling IMO. Bus transportation is not offered to the parks from any of these hotels. It's not necessary; they are all close enough to walk (although PP can tire ones feet after walking the parks all day).
I prefer the GCH.
You will love how compact everything is compared to WDW.