The obvious: Grand Californian is similar to the Wilderness Lodge.
I've never been to WDW, but I've been to DL a bunch of times (we're going this DEC for the first time). From the pictures of the hotels at WDW, none of them really capture the magic of Disney quite like the Disneyland Hotel, though.
GCH is more like WL with a bit of upscale GF thrown in. Disneyland Hotel is like a downscale, not as nice (no great views, no nicely renovated rooms, perhaps a little Disney thrown in,) Contemporary Hotel minus all the energy/excitement of the Contemporary. We've never stayed at Paradise Pier, but I'm thinking that it may be more comparable to a hotel in Downtown Disney than it would be to a WDW hotel.