I have to agree with pretty much everything fidoprincess says! I have stayed at all three and prefer the DLH. In fact, we are using points for nine nights at the DLH in June (and doing two nights before that at the Candy Cane). We will probably be doing a few other things in the area but since our points are "free" it just helped the budget to stay at the DLH even on the days we won't be going to the parks as much. We love both DL and WDW but I also agree with Honeymom in that the
Disneyland Resort is much different than WDW. Not in a bad way, just in a different way. I never get bored at Disneyland, I have stayed as long as 8 nights before. And I never left property in that time. This year our plan is to go to the beach, but we'll see! There's a lot packed into those two parks and DTD is right there as well. And since you are staying onsite, you will have a nice pool area to enjoy. My experience at both DL and WDW is that those days and nights fly by.
I really like the DLH. We have stayed there five times and had great stays each time. As far as theming, its Disney themed with all sorts of subtle touches in the rooms, bathrooms, grounds, etc. But the Grand Californian is more like WDW resort theming with that wow factor in the lobby. Its the only one of the three hotels that was built by Disney, the other two were only taken over by Disney. The GCH was designed by the same architect who did the AKL and WL and it looks and feels very similar. I love the GCH too and one very big plus is that almost all of the rooms have balconies. That is very nice. But I think I just have a special place in my heart for the DLH, it was the first Disney resort we ever stayed at, and we have just always had great stays there. But GCH might be for you since you are used to WDW deluxes, and it definitely has the most "deluxe" feel to it.
I don't think you can go wrong with any of them. But I think for someone who is used to WDW resorts and theming, PP will fit that bill the least. I like it, but only stay there when I want to stay onsite and want to save money. And for some reason, the DLH is currently cheaper on points than the PP which is strange to me. PP also has the fewest dining options of the three and is a longer walk.
And as far as the Disneyland Hotel's pool not being themed, I am not sure I agree with that. The big Peter Pan ship in the middle screams Disney. The GCH pool was also nice. PP's pool is boring and if it didn't have that slide, I doubt it would even draw much of a crowd. I love the grounds of the DLH and as someone else said, the other two have nothing in the way of that. Although the GCH has a nice courtyard area in the middle of it. But there is nothing about any of the three pool areas like Stormalong Bay, sorry! Still, the DLH's is probably the largest, with a main pool as well as the quiet pool area. The GCH has two pools but they are really connected to each other. Whereas the DLH's quiet pool area is separate and is usually very quiet. And they have a sandy area at the quiet pool too. If pool is a biggie, that really makes me think PP is not a good option. My kids love that slide, but there is only so many times you can go down that. It is pretty much the same slide as the one at Boardwalk but it empties into a trough, not the pool.
Good luck with your decision. And know that when you use points at the DLR, you won't have to pay that daily resort fee which includes your parking, athletic club use and internet access. Very nice perk!