You cannot make a wrong choice between any of the three! Although I would probably recommend either the DLH or the GCH. The pool view at the DLH is actually quite nice (have gotten that twice and loved it). Since you are premium view, you will be put on a higher floor. You can see some of the grounds as well as the pool. The DTD view at the DLH is wonderful, that way you can see the fireworks every night which is a big plus.
I guess I am in the minority, but I prefer the DLH. The rooms are larger, Disney themed and the pool area is really nice. The GCH pool area is also nice but I found our room to be on the small size and a bit dark. The GCH also won't guarantee a bunkbed or daybed room which is not great for my family. Given the age of your youngest who may be in a pack n play or with your and your dh, that may not be a big deal. At the DLH you will either get a daybed or a free rollaway. If you need a third bed at the GCH and don't get the daybed or bunkbed, you get a sleeping bag. The GCH does have balconies in almost all rooms and that is a big plus. Its more on line with a WDW Deluxe although the DLH is also a deluxe level resort (and in fact so is PP).
That entrance into California Adventure via the GCH can be used by all onsite guests. It can save some time if you cut through there on your way in or out of DCA to the GCH or DLH. All three hotels are an easy walking distance to both parks. You will love the proximity and ease of getting around!
I love staying at the DLR hotels on points. That way I avoid paying the daily resort fee (about $12 add'l to your room rate), the high S. Cal sales tax and you will get free wifi in your room, athletic club privildiges and you will also get daily maid service. We have stayed on points four times at
Disneyland and its gotten to be a good deal, far better than it used to be!
With whatever you decide, have fun on your trip!